Background:
1. My previous email provider left the business.
2. I'm running SM 2.49.4 on a 32 bit copy of Debian 9.
3. I needed help from this list to properly configure SM email for
my new providers. Both do things differently than my previous
provider. Also, this process has suggested why I had problems
with my previous provider last year.
[I.E the left pane of the email window now displays the obsolete
account *AND* the account with my new provider.]
4. I'll be setting up an additional "Newsgroup account" in order to
have redundant access to USENET groups while updating the
configuration of my primary newsgroup account.

Possible improvements to "Account Wizard"

"Incoming Server Information"
Modify text requesting "User Name" to clarify that some email servers
expect "jsmith" while others expect "jsmith@xyz.com".

"Outgoing Server information"
Offer choice of:
1. Default Outgoing Server
[Display its "User Name" and server]
2. Activate "Outgoing Server (SMPT) Settings" screen

One thing I would like to do is reproduce only the folder structure of
the obsolete account for the new one.
How?

Where and how are the various email filters stored?
I would like to be able to see them as I create similar filters for my
new provider.

After getting my current SM acting as I desire, I will then update it
and and my OS.
Where will I find instructions for moving a SeaMonkey 2.49.4 profile to
the current version?

TIA

Richard Owlett wrote on 24/9/23 8:36 pm:
> Background:
>    1. My previous email provider left the business.
>    2. I'm running SM 2.49.4 on a 32 bit copy of Debian 9.
>    3. I needed help from this list to properly configure SM email for
>       my new providers. Both do things differently than my previous
>       provider. Also, this process has suggested why I had problems
>       with my previous provider last year.
>       [I.E the left pane of the email window now displays the obsolete
>        account *AND* the account with my new provider.]

If you want to remove/delete the old account, go to Edit -> Mail &
Newsgroup Account Settings, select the account you wish to delete then
click the "Remove Account" button on the lower left of that screen.

>    4. I'll be setting up an additional "Newsgroup account" in order to
>       have redundant access to USENET groups while updating the
>       configuration of my primary newsgroup account.
>
>
> Possible improvements to "Account Wizard"
>
> "Incoming Server Information"
> Modify text requesting "User Name" to clarify that some email servers
> expect "jsmith" while others expect "jsmith@xyz.com".
>
> "Outgoing Server information"
> Offer choice of:
>   1. Default Outgoing Server
>      [Display its "User Name" and server]
>   2. Activate "Outgoing Server (SMPT) Settings" screen
>
>
> One thing I would like to do is reproduce only the folder structure of
> the obsolete account for the new one.
> How?

Isn't that automatic?? Or do you mean that the 'new' account structure
should reflect the structure of the old account .... including any added
folders, etc??

> Where and how are the various email filters stored?
> I would like to be able to see them as I create similar filters for my
> new provider.

Tools -> Message filters .... on a per account/newsgroup basis. If you
want a filter to apply to every newsgroup in an account, go to the top
of the list of newsgroup and the account should be listed there.

> After getting my current SM acting as I desire, I will then update it
> and and my OS.
> Where will I find instructions for moving a SeaMonkey 2.49.4 profile to
> the current version?

In your SM 2.49.4, take note of the location shown at the bottom of that
screen 'Local directory:' on the 'Server Settings' screen of your old
e-mail account.

Go to the same location in your current version of SM and take note of
that location, there, as well.

BACK UP BOTH SETS OF FILE TO SOMEWHERE ELSE ... you know, JUST IN CASE!!

Then close both SM's and go to that (old) location in your OS File
Manager (I use Dolphin on my MageiaLinux!) and copy that Profile then go
to the (new) location and paste the 'old' over the 'new'.

> TIA
>
HTH.
--
Daniel

On 09/24/2023 07:07 AM, Daniel65 wrote:
> Richard Owlett wrote on 24/9/23 8:36 pm:
>> Background:
>>     1. My previous email provider left the business.
>>     2. I'm running SM 2.49.4 on a 32 bit copy of Debian 9.
>>     3. I needed help from this list to properly configure SM email for
>>        my new providers. Both do things differently than my previous
>>        provider. Also, this process has suggested why I had problems
>>        with my previous provider last year.
>>        [I.E the left pane of the email window now displays the obsolete
>>         account *AND* the account with my new provider.]
>
> If you want to remove/delete the old account, go to Edit -> Mail &
> Newsgroup Account Settings, select the account you wish to delete then
> click the "Remove Account" button on the lower left of that screen.

I explicitly want to keep it conveniently available.
The messages have important content.

>
>>     4. I'll be setting up an additional "Newsgroup account" in order to
>>        have redundant access to USENET groups while updating the
>>        configuration of my primary newsgroup account.
>>
>>
>> Possible improvements to "Account Wizard"
>>
>> "Incoming Server Information"
>> Modify text requesting "User Name" to clarify that some email servers
>> expect "jsmith" while others expect "jsmith@xyz.com".
>>
>> "Outgoing Server information"
>> Offer choice of:
>>    1. Default Outgoing Server
>>       [Display its "User Name" and server]
>>    2. Activate "Outgoing Server (SMPT) Settings" screen
>>
>>
>> One thing I would like to do is reproduce only the folder structure of
>> the obsolete account for the new one.
>> How?
>
> Isn't that automatic?? Or do you mean that the 'new' account structure
> should reflect the structure of the old account .... including any added
> folders, etc??

I want the new account to start with folder structure of the old
account. I will then tweak the new account's structure to reflect
experience gained with the old structure.

>
>> Where and how are the various email filters stored?
>> I would like to be able to see them as I create similar filters for my
>> new provider.
>
> Tools -> Message filters .... on a per account/newsgroup basis. If you
> want a filter to apply to every newsgroup in an account, go to the top
> of the list of newsgroup and the account should be listed there.

It's there in a unusable format. Think of it as asking for a physical
printout of each filters name, selection criteria, and action performed.

>
>> After getting my current SM acting as I desire, I will then update it
>> and and my OS.
>> Where will I find instructions for moving a SeaMonkey 2.49.4 profile
>> to the current version?
>
> In your SM 2.49.4, take note of the location shown at the bottom of that
> screen 'Local directory:' on the 'Server Settings' screen of your old
> e-mail account.
>
> Go to the same location in your current version of SM and take note of
> that location, there, as well.
>
> BACK UP BOTH SETS OF FILE TO SOMEWHERE ELSE ... you know, JUST IN CASE!!
>
> Then close both SM's and go to that (old) location in your OS File
> Manager (I use Dolphin on my MageiaLinux!) and copy that Profile then go
> to the (new) location and paste the 'old' over the 'new'.

HUH????????
But I see constant warnings that SeaMonkey 2.49.4 profiles are
physically incompatible with current SeaMonkey release.

>
>> TIA
>>
> HTH.

Richard Owlett wrote on 24/9/23 10:55 pm:
> On 09/24/2023 07:07 AM, Daniel65 wrote:
>> Richard Owlett wrote on 24/9/23 8:36 pm:
>>> Background:
>>>     1. My previous email provider left the business.
>>>     2. I'm running SM 2.49.4 on a 32 bit copy of Debian 9.
>>>     3. I needed help from this list to properly configure SM email for
>>>        my new providers. Both do things differently than my previous
>>>        provider. Also, this process has suggested why I had problems
>>>        with my previous provider last year.
>>>        [I.E the left pane of the email window now displays the
>>>        obsolete account *AND* the account with my new provider.]
>>
>> If you want to remove/delete the old account, go to Edit -> Mail &
>> Newsgroup Account Settings, select the account you wish to delete then
>> click the "Remove Account" button on the lower left of that screen.
>
> I explicitly want to keep it conveniently available.
> The messages have important content.

O.K., changing the order that the various email and news account are
listed in can be done by fiddling in the configuration fole using
'about:config' but I've forgotten how I did it in the past so,
hopefully, someone more knowledgeable in that respect will drop by.

>>>     4. I'll be setting up an additional "Newsgroup account" in order
>>>        to have redundant access to USENET groups while updating the
>>>        configuration of my primary newsgroup account.
>>>
>>>
>>> Possible improvements to "Account Wizard"
>>>
>>> "Incoming Server Information"
>>> Modify text requesting "User Name" to clarify that some email servers
>>> expect "jsmith" while others expect "jsmith@xyz.com".
>>>
>>> "Outgoing Server information"
>>> Offer choice of:
>>>    1. Default Outgoing Server
>>>       [Display its "User Name" and server]
>>>    2. Activate "Outgoing Server (SMPT) Settings" screen
>>>
>>>
>>> One thing I would like to do is reproduce only the folder structure
>>> of the obsolete account for the new one.
>>> How?
>>
>> Isn't that automatic?? Or do you mean that the 'new' account structure
>> should reflect the structure of the old account .... including any
>> added folders, etc??
>
> I want the new account to start with folder structure of the old
> account. I will then tweak the new account's structure to reflect
> experience gained with the old structure.

I don't know if that is possible. I think they'll just start with a
stock-standard structure.

>>> Where and how are the various email filters stored?
>>> I would like to be able to see them as I create similar filters for
>>> my new provider.
>>
>> Tools -> Message filters .... on a per account/newsgroup basis. If you
>> want a filter to apply to every newsgroup in an account, go to the top
>> of the list of newsgroup and the account should be listed there.
>
> It's there in a unusable format. Think of it as asking for a physical
> printout of each filters name, selection criteria, and action
> performed.

Sorry, can't help.

>>> After getting my current SM acting as I desire, I will then update it
>>> and and my OS.
>>> Where will I find instructions for moving a SeaMonkey 2.49.4 profile
>>> to the current version?
>>
>> In your SM 2.49.4, take note of the location shown at the bottom of
>> that screen 'Local directory:' on the 'Server Settings' screen of your
>> old e-mail account.
>>
>> Go to the same location in your current version of SM and take note of
>> that location, there, as well.
>>
>> BACK UP BOTH SETS OF FILE TO SOMEWHERE ELSE ... you know, JUST IN
>> CASE!!
>>
>> Then close both SM's and go to that (old) location in your OS File
>> Manager (I use Dolphin on my MageiaLinux!) and copy that Profile then
>> go to the (new) location and paste the 'old' over the 'new'.
>
> HUH????????
> But I see constant warnings that SeaMonkey 2.49.4 profiles are
> physically incompatible with current SeaMonkey release.

Different stuff has been done along the way but, as I understand it, the
files which contain the actual e-mails, etc., are still the same. It
might just be the way they are handled that has changed.

>>> TIA
>>>
>> HTH.

--
Daniel

On 09/25/2023 05:14 AM, Daniel65 wrote:
> Richard Owlett wrote on 24/9/23 10:55 pm:
>> On 09/24/2023 07:07 AM, Daniel65 wrote:
>>> Richard Owlett wrote on 24/9/23 8:36 pm:
>>>> Background:
>>>>     1. My previous email provider left the business.
>>>>     2. I'm running SM 2.49.4 on a 32 bit copy of Debian 9.
>>>>     3. I needed help from this list to properly configure SM email for
>>>>        my new providers. Both do things differently than my previous
>>>>        provider. Also, this process has suggested why I had problems
>>>>        with my previous provider last year.
>>>>        [I.E the left pane of the email window now displays the
>>>>        obsolete account *AND* the account with my new provider.]
>>>
>>> If you want to remove/delete the old account, go to Edit -> Mail &
>>> Newsgroup Account Settings, select the account you wish to delete
>>> then click the "Remove Account" button on the lower left of that screen.
>>
>> I explicitly want to keep it conveniently available.
>> The messages have important content.
>
> O.K., changing the order that the various email and news account are
> listed in can be done by fiddling in the configuration fole using
> 'about:config' but I've forgotten how I did it in the past so,
> hopefully, someone more knowledgeable in that respect will drop by.
>

Who said anything about changing the order accounts listed?
In fact old at top and new at bottom is logical.
Are you misreading my item #3 above, in which state that this group
*HAD* provided information I *HAD* needed ?

>>>>     4. I'll be setting up an additional "Newsgroup account" in order
>>>>        to have redundant access to USENET groups while updating the
>>>>        configuration of my primary newsgroup account.
>>>>
>>>>
>>>> Possible improvements to "Account Wizard"
>>>>
>>>> "Incoming Server Information"
>>>> Modify text requesting "User Name" to clarify that some email
>>>> servers expect "jsmith" while others expect "jsmith@xyz.com".
>>>>
>>>> "Outgoing Server information"
>>>> Offer choice of:
>>>>    1. Default Outgoing Server
>>>>       [Display its "User Name" and server]
>>>>    2. Activate "Outgoing Server (SMPT) Settings" screen
>>>>
>>>>
>>>> One thing I would like to do is reproduce only the folder structure
>>>> of the obsolete account for the new one.
>>>> How?
>>>
>>> Isn't that automatic?? Or do you mean that the 'new' account
>>> structure should reflect the structure of the old account ....
>>> including any added folders, etc??
>>
>> I want the new account to start with folder structure of the old
>> account. I will then tweak the new account's structure to reflect
>> experience gained with the old structure.
>
> I don't know if that is possible. I think they'll just start with a
> stock-standard structure.
>
>>>> Where and how are the various email filters stored?
>>>> I would like to be able to see them as I create similar filters for
>>>> my new provider.
>>>
>>> Tools -> Message filters .... on a per account/newsgroup basis. If
>>> you want a filter to apply to every newsgroup in an account, go to
>>> the top of the list of newsgroup and the account should be listed there.
>>
>> It's there in a unusable format. Think of it as asking for a physical
>> printout of each filters name, selection criteria, and action performed.
>
> Sorry, can't help.
>
>>>> After getting my current SM acting as I desire, I will then update
>>>> it and and my OS.
>>>> Where will I find instructions for moving a SeaMonkey 2.49.4 profile
>>>> to the current version?
>>>
>>> In your SM 2.49.4, take note of the location shown at the bottom of
>>> that screen 'Local directory:' on the 'Server Settings' screen of
>>> your old e-mail account.
>>>
>>> Go to the same location in your current version of SM and take note
>>> of that location, there, as well.
>>>
>>> BACK UP BOTH SETS OF FILE TO SOMEWHERE ELSE ... you know, JUST IN CASE!!
> >>
>>> Then close both SM's and go to that (old) location in your OS File
>>> Manager (I use Dolphin on my MageiaLinux!) and copy that Profile then
>>> go to the (new) location and paste the 'old' over the 'new'.
>>
>> HUH????????
>> But I see constant warnings that SeaMonkey 2.49.4 profiles are
>> physically incompatible with current SeaMonkey release.
>
> Different stuff has been done along the way but, as I understand it, the
> files which contain the actual e-mails, etc., are still the same. It
> might just be the way they are handled that has changed.
>

Yes, things are unclear.
I was hoping to be pointed to some sort of "official howto".
I'll start a separate thread on this question.
The solution may be a rephrasing introduction of Release Notes or adding
a menu item to a general article on how/why to migrate profiles.

Thanks for your time and helping reformulate my questions.
I don't have a software background, thought patterns prompted by decades
in QA/QC.

>>>> TIA
>>>>
>>> HTH.
>

On 09/26/2023 05:35 AM, Richard Owlett wrote:
> On 09/25/2023 05:14 AM, Daniel65 wrote:
> *SNIP*
>>>> Then close both SM's and go to that (old) location in your OS File
>>>> Manager (I use Dolphin on my MageiaLinux!) and copy that Profile
>>>> then go to the (new) location and paste the 'old' over the 'new'.
>>>
>>> HUH????????
>>> But I see constant warnings that SeaMonkey 2.49.4 profiles are
>>> physically incompatible with current SeaMonkey release.
>>
>> Different stuff has been done along the way but, as I understand it,
>> the files which contain the actual e-mails, etc., are still the same.
>> It might just be the way they are handled that has changed.
>>
>
> Yes, things are unclear.
> I was hoping to be pointed to some sort of "official howto".
> I'll start a separate thread on this question.
> The solution may be a rephrasing introduction of Release Notes or adding
> a menu item to a general article on how/why to migrate profiles.

There is scattered (complete?) information on profile migration.
https://www.seamonkey-project.org/doc/profiles#migrate
Entry for "Migrating profiles" should say "...to migrate a profile
from Netscape, Mozilla, Thunderbird or previous SeaMonkey
releases."
http://kb.mozillazine.org/Profile_migration_-_SeaMonkey
[linked in above page]
OBSOLETE - last update " 4 October 2010, at 21:53."

>
> Thanks for your time and helping reformulate my questions.
> I don't have a software background, thought patterns prompted by decades
> in QA/QC.
>
>>>>> TIA
>>>>>
>>>> HTH.
>>
>
>

Richard Owlett wrote on 26/9/23 8:35 pm:
> On 09/25/2023 05:14 AM, Daniel65 wrote:
>> Richard Owlett wrote on 24/9/23 10:55 pm:
>>> On 09/24/2023 07:07 AM, Daniel65 wrote:
>>>> Richard Owlett wrote on 24/9/23 8:36 pm:
>>>>> Background: 1. My previous email provider left the business.
>>>>> 2. I'm running SM 2.49.4 on a 32 bit copy of Debian 9. 3. I
>>>>> needed help from this list to properly configure SM email
>>>>> for my new providers. Both do things differently than my
>>>>> previous provider. Also, this process has suggested why I had
>>>>> problems with my previous provider last year. [I.E the left
>>>>> pane of the email window now displays the obsolete account
>>>>> *AND* the account with my new provider.]
>>>>
>>>> If you want to remove/delete the old account, go to Edit ->
>>>> Mail & Newsgroup Account Settings, select the account you wish
>>>> to delete then click the "Remove Account" button on the lower
>>>> left of that screen.
>>>
>>> I explicitly want to keep it conveniently available. The messages
>>> have important content.
>>
>> O.K., changing the order that the various email and news account
>> are listed in can be done by fiddling in the configuration fole
>> using 'about:config' but I've forgotten how I did it in the past
>> so, hopefully, someone more knowledgeable in that respect will drop
>> by.
>
> Who said anything about changing the order accounts listed? In fact
> old at top and new at bottom is logical. Are you misreading my item
> #3 above, in which state that this group *HAD* provided information I
> *HAD* needed ?

Yes, I may have been misreading your item #3 above .... particularly
your "[I.E the left pane of the email window now displays the obsolete
account *AND* the account with my new provider.]" which I took to mean
you wanted to re-order your accounts so those you mainly deal with are
at the top and the old accounts are at the bottom.

<Snip>

--
Daniel

Richard Owlett wrote:
> On 09/25/2023 05:14 AM, Daniel65 wrote:
>> Richard Owlett wrote on 24/9/23 10:55 pm:
>>> On 09/24/2023 07:07 AM, Daniel65 wrote:
>>>> Richard Owlett wrote on 24/9/23 8:36 pm:
>>>>> After getting my current SM acting as I desire, I will then update
>>>>> it and and my OS.
>>>>> Where will I find instructions for moving a SeaMonkey 2.49.4
>>>>> profile to the current version?
>>>>
>>>> In your SM 2.49.4, take note of the location shown at the bottom of
>>>> that screen 'Local directory:' on the 'Server Settings' screen of
>>>> your old e-mail account.

That's where the files containing the messages (and a few other things)
for a particular mail/news account are stored. The server settings etc.
are not stored there - they're in the prefs.js file in the main profile
directory (which is what you're editing when you go to about:config).

The path for the profile as a whole is found under Help >
Troubleshooting Information and look at the "Profile Directory" path.
All the profile data, including messages for all mail/news accounts,
will be under that directory - UNLESS you've specifically chosen to
store some bits of the profile elsewhere (which isn't recommended and if
you've done that you should know what you're doing / have done). This
is the one you should back up.

>>>> Go to the same location in your current version of SM and take note
>>>> of that location, there, as well.
>>>>
>>>> BACK UP BOTH SETS OF FILE TO SOMEWHERE ELSE ... you know, JUST IN
>>>> CASE!!
>> >>
>>>> Then close both SM's and go to that (old) location in your OS File
>>>> Manager (I use Dolphin on my MageiaLinux!) and copy that Profile
>>>> then go to the (new) location and paste the 'old' over the 'new'.
>>>
>>> HUH????????
>>> But I see constant warnings that SeaMonkey 2.49.4 profiles are
>>> physically incompatible with current SeaMonkey release.
>>
>> Different stuff has been done along the way but, as I understand it,
>> the files which contain the actual e-mails, etc., are still the same.
>> It might just be the way they are handled that has changed.

In theory, anything about the profile format *could* change between one
version and the next. In practice, it's usually things like the
database formats used for passwords, bookmarks, etc. that tend to
change, and the folder structures used for email messages are fairly
stable - but in theory those could change in some future version as well.

> Yes, things are unclear.
> I was hoping to be pointed to some sort of "official howto".
> I'll start a separate thread on this question.
> The solution may be a rephrasing introduction of Release Notes or adding
> a menu item to a general article on how/why to migrate profiles.
>
> Thanks for your time and helping reformulate my questions.
> I don't have a software background, thought patterns prompted by decades
> in QA/QC.

The short answer is:
* Updating from an older version to a newer one is usually OK, and
profiles should be converted to the newer format as needed.
* Check the release notes if skipping versions, in case you need to
update via an intermediate release.
* Downgrading from a newer version to an older one is not recommended
and could result in data loss.
* It's a good idea to back up your profile before updating, just in case
something goes wrong with the conversion or something else means you
need to go back to the old version.

In more detail...

Newer versions of SeaMonkey usually have code to convert any files from
an old profile into the newer format. So the first time you start
SeaMonkey after an update, the default profile gets updated to the newer
format. Any other profiles will get converted as and when you use them.

Older versions of SeaMonkey won't understand newer formats. So what you
can't do without risking loss of data from the profile, is go back to an
older version after the profile has been loaded in a newer version. The
older version will generally consider the newer format file to be
corrupt, and replace it with a blank version. That will generally only
affect the files whose format had changed, e.g. it might be only
passwords or only bookmarks and history.

For example, between 2.49.5 and a 2.53, the password database formats
were updated. You can use an older profile from before that change in a
newer version of SeaMonkey, and the password database should be
converted to the newer format (in that particular case it's recommended
to remove any master password before updating, as per the release notes,
but that's an extra complication in just that case). However, if you
then use that same profile in 2.49.5 or earlier using, it won't be able
to read the password database, which will probably be replaced with an
empty database - you'd lose all your saved passwords.

In practice, it's sometimes safe to go back and forth if the profile
formats haven't changed. But the SeaMonkey developers don't commit to
that and make no guarantees - something could break in an obvious way
(all your bookmarks or passwords are gone), or it might be something
more subtle. If you want to avoid data loss, the advice is to avoid
using a profile with an older version than it was last used with.

Even when updating to newer versions, it's a good idea to back up the
profile before updating - close SeaMonkey (including the "quick starter"
if that's still a thing) and back up the whole profile directory. If
you've stored bits of the profile in other places, back up those too.
That way, if something goes wrong, you can at least reinstall the old
version and restore the profile from the backup, and will only have lost
anything you'd done since the attempted update.

Sometimes, if skipping several releases, the migration code for the old
version might have been removed and you'd have to update to some
intermediate version first. I think that's usually mentioned in the
release notes. For example, under "System Requirements, Installation
and Uninstallation", the current release 2.53.17.1 notes say:
> SeaMonkey 2.53.17.1 will no longer offer to migrate your data from SeaMonkey 1.x or Mozilla 1.x at the first start after installation (bug 689437). In order to upgrade from such an old version, install the last SeaMonkey 2.0 release first, do the one-time profile upgrade, uninstall SeaMonkey 2.0 and then install your target release (e.g. this one).
> If you are on an older release we suggest upgrading to SeaMonkey 2.49.5 first.

So:
* Close SeaMonkey (including the quick starter)
* Back up your profile
* If you're currently on something older than 2.0:
- Update to 2.0
- Start that version
- (Switch to each profile in turn if you have several)
* Then, or if you're currently on something older than 2.49.5:
- Update to 2.49.5
- Start that version
- (Switch to each profile in turn if you have several)
* Then update to 2.53.17.1

--
Mark.

On 09/26/2023 03:29 PM, Mark Bourne wrote:
> Richard Owlett wrote:
>> On 09/25/2023 05:14 AM, Daniel65 wrote:
>>> Richard Owlett wrote on 24/9/23 10:55 pm:
>>>> On 09/24/2023 07:07 AM, Daniel65 wrote:
>>>>> Richard Owlett wrote on 24/9/23 8:36 pm:
>>>>>> After getting my current SM acting as I desire, I will then update
>>>>>> it and and my OS.
>>>>>> Where will I find instructions for moving a SeaMonkey 2.49.4
>>>>>> profile to the current version?
>>>>>
>>>>> In your SM 2.49.4, take note of the location shown at the bottom of
>>>>> that screen 'Local directory:' on the 'Server Settings' screen of
>>>>> your old e-mail account.
>
> That's where the files containing the messages (and a few other things)
> for a particular mail/news account are stored.  The server settings etc.
> are not stored there - they're in the prefs.js file in the main profile
> directory (which is what you're editing when you go to about:config).
>
> The path for the profile as a whole is found under Help >
> Troubleshooting Information and look at the "Profile Directory" path.
> All the profile data, including messages for all mail/news accounts,
> will be under that directory - UNLESS you've specifically chosen to
> store some bits of the profile elsewhere (which isn't recommended and if
> you've done that you should know what you're doing / have done).  This
> is the one you should back up.
>
>>>>> Go to the same location in your current version of SM and take note
>>>>> of that location, there, as well.
>>>>>
>>>>> BACK UP BOTH SETS OF FILE TO SOMEWHERE ELSE ... you know, JUST IN
>>>>> CASE!!
>>>  >>
>>>>> Then close both SM's and go to that (old) location in your OS File
>>>>> Manager (I use Dolphin on my MageiaLinux!) and copy that Profile
>>>>> then go to the (new) location and paste the 'old' over the 'new'.
>>>>
>>>> HUH????????
>>>> But I see constant warnings that SeaMonkey 2.49.4 profiles are
>>>> physically incompatible with current SeaMonkey release.
>>>
>>> Different stuff has been done along the way but, as I understand it,
>>> the files which contain the actual e-mails, etc., are still the same.
>>> It might just be the way they are handled that has changed.
>
> In theory, anything about the profile format *could* change between one
> version and the next.  In practice, it's usually things like the
> database formats used for passwords, bookmarks, etc. that tend to
> change, and the folder structures used for email messages are fairly
> stable - but in theory those could change in some future version as well.
>
>> Yes, things are unclear.
>> I was hoping to be pointed to some sort of "official howto".
>> I'll start a separate thread on this question.
>> The solution may be a rephrasing introduction of Release Notes or
>> adding a menu item to a general article on how/why to migrate profiles.
>>
>> Thanks for your time and helping reformulate my questions.
>> I don't have a software background, thought patterns prompted by
>> decades in QA/QC.
>
> The short answer is:
> * Updating from an older version to a newer one is usually OK, and
> profiles should be converted to the newer format as needed.
> * Check the release notes if skipping versions, in case you need to
> update via an intermediate release.
> * Downgrading from a newer version to an older one is not recommended
> and could result in data loss.
> * It's a good idea to back up your profile before updating, just in case
> something goes wrong with the conversion or something else means you
> need to go back to the old version.
>
> In more detail...
>
> Newer versions of SeaMonkey usually have code to convert any files from
> an old profile into the newer format.  So the first time you start
> SeaMonkey after an update, the default profile gets updated to the newer
> format.  Any other profiles will get converted as and when you use them.
>
> Older versions of SeaMonkey won't understand newer formats.  So what you
> can't do without risking loss of data from the profile, is go back to an
> older version after the profile has been loaded in a newer version.  The
> older version will generally consider the newer format file to be
> corrupt, and replace it with a blank version.  That will generally only
> affect the files whose format had changed, e.g. it might be only
> passwords or only bookmarks and history.
>
> For example, between 2.49.5 and a 2.53, the password database formats
> were updated.  You can use an older profile from before that change in a
> newer version of SeaMonkey, and the password database should be
> converted to the newer format (in that particular case it's recommended
> to remove any master password before updating, as per the release notes,
> but that's an extra complication in just that case).  However, if you
> then use that same profile in 2.49.5 or earlier using, it won't be able
> to read the password database, which will probably be replaced with an
> empty database - you'd lose all your saved passwords.
>
>
> In practice, it's sometimes safe to go back and forth if the profile
> formats haven't changed.  But the SeaMonkey developers don't commit to
> that and make no guarantees - something could break in an obvious way
> (all your bookmarks or passwords are gone), or it might be something
> more subtle.  If you want to avoid data loss, the advice is to avoid
> using a profile with an older version than it was last used with.
>
> Even when updating to newer versions, it's a good idea to back up the
> profile before updating - close SeaMonkey (including the "quick starter"
> if that's still a thing) and back up the whole profile directory. If
> you've stored bits of the profile in other places, back up those too.
> That way, if something goes wrong, you can at least reinstall the old
> version and restore the profile from the backup, and will only have lost
> anything you'd done since the attempted update.
>
>
> Sometimes, if skipping several releases, the migration code for the old
> version might have been removed and you'd have to update to some
> intermediate version first.  I think that's usually mentioned in the
> release notes.  For example, under "System Requirements, Installation
> and Uninstallation", the current release 2.53.17.1 notes say:
>> SeaMonkey 2.53.17.1 will no longer offer to migrate your data from
>> SeaMonkey 1.x or Mozilla 1.x at the first start after installation
>> (bug 689437). In order to upgrade from such an old version, install
>> the last SeaMonkey 2.0 release first, do the one-time profile upgrade,
>> uninstall SeaMonkey 2.0 and then install your target release (e.g.
>> this one).
>>  If you are on an older release we suggest upgrading to SeaMonkey
>> 2.49.5 first.
>
> So:
> * Close SeaMonkey (including the quick starter)
> * Back up your profile
> * If you're currently on something older than 2.0:
>     - Update to 2.0
>     - Start that version
>     - (Switch to each profile in turn if you have several)
> * Then, or if you're currently on something older than 2.49.5:
>     - Update to 2.49.5
>     - Start that version
>     - (Switch to each profile in turn if you have several)
> * Then update to 2.53.17.1
>
>

Thank you.
I suspect I'll spend this weekend parsing your and Daniel's input into
sub-tasks of a couple of my current projects.