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

Thunderbird E mail authentication when sending emails

  • 1 reply
  • 0 have this problem
  • 1 view
  • Last reply by david

more options

When I try to send emails, I receive this message. "Sending of the message failed. An error occurred while sending mail. The mail server responded: [M1] Authentication required (6aecbed3-07a6-11ef-9de7-83bcbd00a978). Please verify that your email address is correct in your account settings and try again". I have checked as requested by this message, and everything appears to be in order. Can anyone help with this issue, please?

When I try to send emails, I receive this message. "Sending of the message failed. An error occurred while sending mail. The mail server responded: [M1] Authentication required (6aecbed3-07a6-11ef-9de7-83bcbd00a978). Please verify that your email address is correct in your account settings and try again". I have checked as requested by this message, and everything appears to be in order. Can anyone help with this issue, please?

All Replies (1)

more options

Maybe we can assist if you share screenshots of input server settings and SMTP server settings. Thank you.