Is this a new setup? Maybe if you post a screenshot of the SMTP server settings and the incoming server settings, some ideas on this may surface. Thank you.

Thank you for your response. It has been solved! Don't know how, to be honest. I deleted the password in the Thunderbird memory and entered again via the Google account. And then it worked.

I too am having this same problem, nor receiving or sending emails, exact same thing on authentication. I'm also having a strange popup each time I load thunderbird? I don't know how to change password either.

I'm using Thunderbird 115.7.0 (64 bits). Cannot send messages from my email account: [edited[] @gmail.com. It says it cannot make connection to server smtp.gmail.com. Not Receiving emails or sending. Looks like there is something wrong with the authentication. Also getting a popup picture from AOL?

Tis is not solved. This same issue has sprung up for after the last update. Will not send: do to accepting server detects spam like characters in the email. Sent a clean email IE: no signature, it produces a password issue, which upon investigation, is the correct password. Last error with a plain jane email, no links or signature or code for signature box, the smtp server times out.

ports are correct 587 or 465 starttls and plain password. Authentication process is set correct to isp protocol could installation have become corrupt? not running any email scanners or email virus programs

mail will send from isp webmail page. Deleted all passwords from all accounts in thunderbird and put them back in via restart and popup to authenticate. All authenticated but cannot send plain email. times out

ThunderBird issue since last update. Is there a correction for his issue? This is not a config issue as I have gone through the settings with isp. Most likely an update issue or corruption issue since last update. Been running thunderbird for many years

This thread has been marked resolved. For new issues, please open new posts. Thank you.