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GPG4win exchange issue decrypt message from Macos GPGtools
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We are facing big issue in our company, when we receive encrypted message from macos with gpgtools from applemail, we cant decryp it, but only from different tenant, where is it same domain its ok.

It should be something with content-type in header of email, because thunderbird can repair this content-type issue with pop up, when email is opened, but outlook with GPG4win cant handle it.

Can you help me please ?



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werner added a subscriber: werner.

Looks more like a support question but feel free to create a sample message, encrypt it to info at (WKD) and attach that message to this report.

werner triaged this task as Normal priority.Aug 29 2023, 9:55 AM

I was trying to solve it with support, but it was not solved until today, this issue we are facing more thank like 2years.
I guess its need to be solved with more advanced support than classic one.

Hi, my suspicion with the different tenant is that some middleware of yours is inserting something like "DANGER this could not be Virus Scanned by your super secure and expensive middleware" which then results in the mail beeing multipart/mixed instead of pgp/encrypted in the MIME type. Could you ask your communication partner with the problem to send such a mail to you and with CC to "


I kind of bet that I will be able to decrypt the mail, if not we have a real compatibility issue that I would fix. If yes you could in theory export your mail to a .msg file and send it to me in a zip file (so it does not get modified in transfer) and I could point out exactly why it won't decrypt for you. But that would indeed be support which we is usually reserved for customers of GnuPG (VS) Desktop.


thank you, i send you test mail

Well the message is content-type multipart/mixed. For GpgOL to investigate the mail it needs to be multipart/signed oder application/encrypted or application/pgp-encrypted. (and some other things) But multipart/mixed is something that we don't take a second look at because this means "unencrypted mail with attachments."

I don't think gpgtools is to blame here. I still suspect some middleware, even though your mail is empty. Because if you have that for about 2 years and it has not been reported here that does not sound like a recent development and I exchanged mails with gpgtools users in the meantime and it worked. They always have problems with new MacOS versions but that again would speak against the two years.

But you are somewhat in luck with the next Gpg4win update there will be a new feature in Kleopatra that opens the "OpenPGP encrypted message.asc" in a kind of mail viewer so that you can then still read the attachments and contents. I am closing this as a duplicate of another issue, because that one is technically the same even if the description is different.

aheinecke changed the task status from Duplicate to Resolved.Sep 1 2023, 7:51 PM

Ah damn, now that I closed this as a duplicate I found that we already have code to handle this problem.

Will be fixed in the next release. Your test message was correctly detected as an encrypted message. I just couldn't decrypt it as I accidentally sent you the wrong demo key :) But it shows the "OpenPGP encrypted message" and to which keys it is encrypted now.

So by we already have code to handle this problem, we had code for "No body but multipart/mixed" and your message was "empty body but multipart mixed" so I just needed to also check for an empty body and the code worked.


i dont get any responce, what is next step in this case.

I guess you need to wait until we do a new release. If your company relies on this software it might be a good idea to enter into a support contract as other do.

Ok and its possible to know, how long its should usually take to make new release ?
Can you tell me more about support contract or when i can find more information about it ?

Please try the following beta: This should solve your problem. And if not you can now open the encrypted attachments with Kleopatra and it will show your mail.

Thank you very much, we will try it and let you know

Hi, thank you so much and sorry for delay.
This beta is working for us perfectly.

We find out another issue, we trying to use Canary Mail, but when we send email outside internal domain we have same issue as we had before (windows users cant decrypt it).
Also i have little more question, in GPG4win is propably issue with czech language ? Is there any way how to handle this ?