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

Thunderbirs SMTP error

  • 1 reply
  • 2 have this problem
  • 3 views
  • Last reply by benheuser

more options

Since this morning I am unable to send Mail via Thunderbird. I am getting the error message:

'Sending of the message failed. The message could not be sent because connecting to Outgoing server (SMTP) securesmtp.t-online.de failed. The server may be unavailable or is refusing SMTP connections. Please verify that your Outgoing server (SMTP) settings are correct and try again'

I can still receive emails and I can send emails with the same outgoing server settings from a mobile device in the same WIFI. I tried re-adding one of the accounts. This problem occurs on all my email accounts.

I am working on Ubuntu 20.04 and have installed Thunderbird version 102.9.0.

Since this morning I am unable to send Mail via Thunderbird. I am getting the error message: 'Sending of the message failed. The message could not be sent because connecting to Outgoing server (SMTP) securesmtp.t-online.de failed. The server may be unavailable or is refusing SMTP connections. Please verify that your Outgoing server (SMTP) settings are correct and try again' I can still receive emails and I can send emails with the same outgoing server settings from a mobile device in the same WIFI. I tried re-adding one of the accounts. This problem occurs on all my email accounts. I am working on Ubuntu 20.04 and have installed Thunderbird version 102.9.0.

Chosen solution

The problem resolved itself after a few hours. I still don't know the reason.

Read this answer in context 👍 0

All Replies (1)

more options

Chosen Solution

The problem resolved itself after a few hours. I still don't know the reason.