We're calling on all EU-based Mozillians with iOS or iPadOS devices to help us monitor Apple’s new browser choice screens. Join the effort to hold Big Tech to account!

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

Sending of the message failed. The message could not be sent because the connection to Outgoing server (SMTP) smtp.office365.com timed out. Try again.

more options

For Thunderbird: I can receive e-mails. Error on sending. Message below. Output settings were fine last week. This is affecting several people at Kansas State University. With Pegasus e-mail, extending the timeout to 90 seconds seems to work. Can the timeout be extended in Thunderbird?

Error Message: Sending of the message failed. The message could not be sent because the connection to Outgoing server (SMTP) smtp.office365.com timed out. Try again.

Thanks.

For Thunderbird: I can receive e-mails. Error on sending. Message below. Output settings were fine last week. This is affecting several people at Kansas State University. With Pegasus e-mail, extending the timeout to 90 seconds seems to work. Can the timeout be extended in Thunderbird? Error Message: Sending of the message failed. The message could not be sent because the connection to Outgoing server (SMTP) smtp.office365.com timed out. Try again. Thanks.
Attached screenshots

All Replies (3)

more options

Is there a security program scanning outgoing mail or controlling SSL connections? The timeout is set by the mailnews.tcptimeout preference in Config. editor, but the default is already 100 sec.

more options

Is there a security program scanning outgoing mail or controlling SSL connections? The timeout is set by the mailnews.tcptimeout preference in Config. editor, but the default is already 100 sec.

more options

The problem was fix on our end. Our campus has been hit with several phishing scams that triggered our connection to smtp.office365.com to be blocked. Forces that be unblocked this problem. Thanks for the feedback. It's good to know of the 100 sec. timeout.