I had recently changed to using SSL with the Hermes extensions. I could send email until I moved to a new location and was blocked for MY IP address being blacklisted. I'm in Airbnb so I can't really pound on the ISP to resolve the issue. Spamhaus has a good page on resolving this, but it's under "running my own email server". I didn't think that was what I was doing, but eventually followed that path and found this info.

https://www.spamhaus.org/faq/section/Spamhaus%2520PBL#183

The section, "Enabling SMTP Authentication" didn't seem to apply, but I worked on this for a bit and eventually found a solution.

I use three email accounts for incoming email. I have some dozen email addressed for outgoing email because of my work. The outgoing email addresses use the same mailbox account for logging in. What I didn't realize was that it was not sufficient for authentication for the three incoming accounts to be different from the outgoing accounts. So on each outgoing account, I set up the incoming email to use authentication, the correct port address, etc. Now my outgoing emails are no longer blocked for SPAM even though I am on a blacklisted IP address.

I still have a problem with one of my vendors who is using Spamhaus for blocking emails. I know they recently overhauled their emails as we had a bit of trouble a few weeks back. Nothing that bounced back to me, but they didn't get all of my emails. I guess the spamhaus thing is part of the new setup.

I'm posting partly to help anyone else with similar problems, but also to document what happened to me and how to fix it, in case it raises its ugly head again, later.

Rick C