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Error sending mails following update to 78.4.0.

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  • Last reply by Mark-E-H

Mark-E-H
Mark-E-H
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This morning Thunderbird was updated to 78.4.0. Incoming mails (POP3) work fine. But suddenly outgoing mails are rejected: "An error occurred while sending mail. The mail server responded 450 4.1.8 <my email>: Sender address rejected: Domain not found. Please check the message recipient ".... recipient ..." and try again.

Sending mails worked fine till update was installed, and I have not changed any SMTP settings. Same error for all recipients of mail.

Any suggestions?

This morning Thunderbird was updated to 78.4.0. Incoming mails (POP3) work fine. But suddenly outgoing mails are rejected: "An error occurred while sending mail. The mail server responded 450 4.1.8 <my email>: Sender address rejected: Domain not found. Please check the message recipient ".... recipient ..." and try again. Sending mails worked fine till update was installed, and I have not changed any SMTP settings. Same error for all recipients of mail. Any suggestions?

Chosen solution

Turned out to be a problem with the provider. Problem is solved.

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Mark-E-H
Mark-E-H Question owner
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Chosen Solution

Turned out to be a problem with the provider. Problem is solved.