My test works now with this commit.

I think the problem is with the selction change event. When we query for selection item (1) we trigger an itemLoad event which apparently causes this behavior. I've disabled everything else in our event handling code so we don't touch the mail at all (non crypto mails we never touch much).

Thanks for the test and the example mail. Should also be fixed now.
While testing I also noticed that the sender email address was also not parsed correctly for these kind of mails and added some code to fix that.

Thank you. With that message I could reproduce the problem and have a fix. I now get to decryption failed / no secret key as it should be.

Thanks for your report and analysis.

Just to be clear I think this issue is valid and we should add more checksum tools in the future. But I would want them to use libgcrypt and confirm to the standard *sum command line arguments like -c.

Kleopatra can still be used without UI Server connectivity. But this might point to a bigger issue.

My first GUI Idea does not work. From the Ribbon I don't see a way to find the currently used account. I could only look at all accounts that are configured and check the WKS publishing state for all of them.

This is coming along nicely. It might take longer then with Kleopatra if the key is large (as the new resolver does a full keylisting on every start) but that should be OK and we have plans to optimize that anyway.

In my tests this is resolved with the commits mentioned here.

We confirmed in a remote session that the Titus Data Classification plugin ( https://www.titus.com/data-classification-product-collection.php#tmc ) interfered with GpgOL.

It's done. The maintainer of the jabber server will try to automate the renewal in the future.

I sent the maintainer of the jabber server a mail.

Thank you for the test :-/
So back to the drawing board.

The changes are made as described. Could you please try:

Trying to reproduce this / staring down the log, I think I might have found the problem.

I think the reason for this is not Exchange Online but that I was using two explorer Windows and switched between Mails while the decryption on the slow exchange folder was still running. This triggered an invalidate_ui while the parsing was active and that then triggered a write / unload just like in T3523

My current idea is that if GpgOL detects that the provider supports a web key service and one of the following is true:

Does this happen to you for all mails or just some? From the GpgOLXXX.dat I can't see anything wrong.
My expectation is that something goes wrong when updating the plain text into the message viewer. Again, could you please attach the GpgOL Debug output? That might help.