If this problem started Friday then the problem is most likely that Suddenlink has stopped supporting SMTP server on the legacy port 587.

Resolution is to change the values in Thunderbird. Highlight the email account - click on "View Settings for this Account" - Edit SMTP Server. Change the Connection Security to SSL/TSL. Port should now be 465, connection security now SSL/TLS and authentication method now Normal Password. Press okay, press okay and retry.

ssl/tsl port 465 norm pass

Cool all is well, many thanks!!!!

Glad it worked. It really was most unkind of Suddenlink to stop their legacy SMTP server without telling anyone.

Jackb.luddite said

If this problem started Friday then the problem is most likely that Suddenlink has stopped supporting SMTP server on the legacy port 587. Resolution is to change the values in Thunderbird. Highlight the email account - click on "View Settings for this Account" - Edit SMTP Server. Change the Connection Security to SSL/TSL. Port should now be 465, connection security now SSL/TLS and authentication method now Normal Password. Press okay, press okay and retry.

I have this problem as well not being able to send mail without repeatedly having to enter my smtppassword. I use verizon.net which is hosted by AOL. This all started since Thunderbird #68 was installed. My TBird is dead! It will not send any messages. Every once in a while it will go thru after closing reopening, changing from user name only to user [email protected] I have asked via email AOL what could be the problem? I can't believ it is only my problem. By the way, I have 2 laptops and both are doing the same thing. The new version will not record my smtp password for auto logon. I jst keep hetting the popup to enter password time + time + time again. Any help would be appreciated by anyone out here. I could not find a way to open a new thread. Hopefully this will reachout to someone who can help. Thanks, CC