What is the exact error message?

This is an automatically generated Delivery Status Notification.

Delivery to the following recipients failed.

      hans@riemers.de

That's all?

YES, yes, just a mail with that content

There isn't much to tell about the problem without the specific error code. You may contact your email provider for help.

I have the same failure message (without error code). If I use my service providers email service via their website, the email is successful. My service provider thus concludes that the problem must be in the Thunderbird settings and that I may need to reinstall. However, I don't know how to do this without first uninstalling Thunderbird and thus losing all my archived emails and address book.

Thunderbird separates the program installation from the profile with all your mail. Re-installing won't touch the profile unless you deliberately tick the box to remove the profile.

In any case, I think you'll just waste your time re-installing the application.

Many thanks for the reply. If reinstalling won't help, any suggestions on what will? The only conclusion I can draw is to change to Outlook Express.

roddymac,

you aren't the OP for this topic, so you should start your own one for your problem. https://support.mozilla.org/questions/new