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

Uknown error is not a good error message. There is particular reason to stop sendind mail. How to know this reason?

  • 1 reply
  • 1 has this problem
  • 18 views
  • Last reply by christ1

more options

Sending of the message failed. The message could not be sent using Outgoing server (SMTP) mx.uis.kiev.ua for an unknown reason. Please verify that your Outgoing server (SMTP) settings are correct and try again.

This message apears after thunderbird update. Nothing wrong with server. Old version work perfectly. WHAT particular reason not to send message?

Sending of the message failed. The message could not be sent using Outgoing server (SMTP) mx.uis.kiev.ua for an unknown reason. Please verify that your Outgoing server (SMTP) settings are correct and try again. This message apears after thunderbird update. Nothing wrong with server. Old version work perfectly. WHAT particular reason not to send message?

All Replies (1)

more options