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There is one e-mailadress that I cannot send messages to in Thunderbird, but have no problem with in gmail, why?

  • 5 replies
  • 1 has this problem
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  • Last reply by Matt

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Never had any problems with Thunderbird, but now on a new laptop it refuses to send mail to one recipient. I tried to send a message to this recipient with gmail, and the message reached its destination without any problems.

Who can explain why I can send messages to one recipient and not to a different one?

Never had any problems with Thunderbird, but now on a new laptop it refuses to send mail to one recipient. I tried to send a message to this recipient with gmail, and the message reached its destination without any problems. Who can explain why I can send messages to one recipient and not to a different one?

All Replies (5)

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re :refuses to send mail to one recipient

As all other emails are being sent, it sounds as if that particular email is also sent, but a server is rejecting it and sending the message back to you saying it was not delivered for some reason.

Are you getting a Mailor Daemon message back from the server? If yes, it will tell you the reason for none delivery. Post an image of the email which tells you about non delivery.

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Hi Toad, Thanks for your quick help! Attached is an immage of the DSN. Br. Sonja

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The reason as far as the receiving server is concerned is clear. "Body type not supported" but what that means in practice. That is the tough part.

As far as I can figure, the issue with exchange is the use of 7bit MIME. So lets check some things.

try specifically sending an email to that address and setting the character encoding on the format menu to UNICODE. I note the addressyou are sending to is in the Netherlands, they should be big adopters of unicode, but we do see the odd occasion where folk are still using the old windows code pages on their mail and forcing 7bit encoding of the email.

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Hi Matt, Thanks for your input!

But...you are right about the Dutch being big adopters of unicode, so unfortunately this did not solve my problem.

The solution turned out to be this:

Go to Tools Options > Advanced > General > Advanced Configuration > Config Editor and search for mail.strictly_mime press enter to change false into true.

Thanks again!

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I was reluctant to suggest that as i do not see it as a solution. There has to be a better way that you sending garbage formatted email to everyone because one server is incorrectly behaving.

Unfortunately given it is an educational institution you are sending to they are probably married to a decade old Microsoft exchange solution that is obsolete. And that is all their administrator knows.