This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Unable to send mail in Thunderbird 102.6.1 (64 Bit)

  • 1 cavab
  • 3 have this problem
  • 19 views
  • Last reply by david

more options

In Thunderbird why do I receive an error message for an invalid Certificate or the following Error message. - Sending of the message failed. An error occurred while sending mail. The mail server responded: Authentication required. Please verify that your email address is correct in your account settings and try again. error message - Sending of the message failed. An error occurred while sending mail. The mail server responded: Authentication required. Please verify that your email address is correct in your account settings and try again.

In Thunderbird why do I receive an error message for an invalid Certificate or the following Error message. - Sending of the message failed. An error occurred while sending mail. The mail server responded: Authentication required. Please verify that your email address is correct in your account settings and try again. error message - Sending of the message failed. An error occurred while sending mail. The mail server responded: Authentication required. Please verify that your email address is correct in your account settings and try again.

All Replies (1)

more options

The error message seems rather clear. There is likely an error in your account setup. That's why the error appears. Possibly, if you post your account server settings, someone here may suggest an approach.