Windows 10 reached EOS (end of support) on October 14, 2025. If you are on Windows 10, see this article.

Avatar for Username

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

Ati ti èròjà atẹ̀lélànà asì ti fi pamọ́ fọ́jọ́ pípẹ́. Jọ̀wọ́ béèrè ìbéèrè titun bí o bá nílò ìrànwọ́.

Sending of message failed an error occurred while sending mail

  • 2 àwọn èsì
  • 4 ní àwọn ìṣòro yìí
  • 325 views
  • Èsì tí ó kẹ́hìn lọ́wọ́ Wayne Mery
  • Ti tì

robinsmj
robinsmj

Trying to send mail. Getting a message Sending of message failed An error occurred while sending mail. Relaying denied you must check for new mail before sending

Trying to send mail. Getting a message Sending of message failed An error occurred while sending mail. Relaying denied you must check for new mail before sending

All Replies (2)

DavidGG
DavidGG

Looks like your outgoing (SMTP) server uses a form of authentication known as "POP before SMTP", where the mail client (Thunderbird) has to authenticate with the incoming (POP) server first in order to be able to use the SMTP server. The POP authentication remains valid for a few minutes.

You may be able to solve the problem by checking for new mail more frequently (e.g. every 5 mins, maybe 10), or manually checking for mail right before sending.

Wayne Mery
Wayne Mery
  • Top 25 Contributor
  • Moderator

Please use https://support.mozilla.org/en-US/questions/1517369