Display now looks good to me in all cases. We still keep the subject when a reply / forward is done, but that is the same as before. To do this properly I would have to actually do the protected headers sending,.. as then I could automatically flag such a message to be sent with protected headers. But that would be a new feature and I rather work on properly doing BCC sending as the next privacy enhancing feature.

The base64 for the version is not needed. I rebuilt and did a test for that. I was testing with Outlook 2016 to Outlook.com to another exchange server. One of the servers in the chain is converting the mime parts to base64.
The MAPI headers in gpgol are causing the auto-decryption of Symantec to stop checking for the MIME attachments. On internal emails the MAPI format is retained and that causes an issue with the symantec client. When they leave the exchange server the base MIME format is what is sent and that works with the Symantec client.

Using base64 encoding for a fixed format part in us-ascii is not a good idea because in practise many PGP/MIME decoders won't be able to detect and then decyrypt such a message.

note that it *does* sometimes hide the legacy display part, for some messages, including unfortunately-complex -- that's good! -- but maybe this points to some internal inconsistency:

This is fixed now.

Thanks for examination.
Providing an 'untouched .msg' seems to be complicate because OL receives several encrypted mails all day long, so GpgOl must be activated for common use. Additional: To avoid this issue, .txt mode has been deactivated, .html is allowed without downloading foreign items or pictures.

Thanks for the report but I cannot reproduce the issue :-/. In multipart alternative mails GpgOL takes the text part if text mode is set in Outlook.

Fixed

We now have a decent error message for this.

I think this is now resolved.

I think we can fix it by removing the smime attachment from OOM, because we still have it in MAPI, we just never cared that it was also in OOM (where only our decrypted attachments belong) because it was hidden.

Still unresolved...

I have the same effect if I send a signed text-only or HTML email using Outlook 365 and our Exchange 365 and if I view the mail on Outlook on Android. The mail shows no contents only the file. If I view the mail using Outlook 365 on my PC or Windows 10 Mail it looks fine.
If I address it also to my Microsoft account and my Gmail account (using all adresses in the TO: field of the same mail) the email looks normal in the Gmail Android app and (!) in Outlook for Android.
So the same mail - both in the same Outlook for Android app - looks correct in my Microsoft account inbox but only shows the file in my Exchange inbox - in the same Outlook App. Weird… Nokia 7 plus, Android 9, newest patch level (September 2019) and no updates in Google Play Store.
BTW: In Exchange 365 I configured the message flow, default remote domain (there is no other) to never to use Rich Text, always and only HTML.

Today a new signed message from BSI Buerger CERT was received. The PGP signature could be verified by first opening of the document. As I opened the file some hours later again, it failed, as I opened it a third time (shortly after the second time), the signature was verified. Outlook was not closed between the second and third opening. Signature verification appears unstable.

There is no reason for apologies :-). As far as I know this all is open source, freeware and you don't get paid for this, right? So, I simply also try to add my contribution by most precise error reports to help to find the error and am grateful if it will be solved one day in the future :-).

As far as I know this works.

This works but might have created a regression which is tracked in T4701

I still would like to test this some more and work on it. I think the implemnation might still be a bit fragile.

I'll try to look at it this week. Apologies for the delay with this.

Last week GpgOL again destroyed an email with a BSI newsletter - it was shown as empty after I opened it a second time - and the same is true in such cases then in Windows 10 Mail as well as using Outlook Web Access:

The signature of the latest communication from German Buerger CERT Warnings could be read and the signature could be verified. I tried also with Hasso-Plattner-Institute (Identiy leak checker), the same result. I do not understand, why all signature verification failed last week, and they can be verified this week. However, at the moment it seems to work fine.

I have the same problem since today with Outlook 2016. In the past months / weeks GpgOL version 2.4.2 worked fine. I received some mails today signed by the German Buerger CERT warnings. The signature as "asc" file was attached, but could not be verified. Today I received also a PGP signed e-mail from Hasso-Plattner-Institute (Identity leak checker), also this signature could not be checked. Both worked fine in the past and the public keys stored in Kleopatra are valid.

If helpful I can demonstrate or let you debug in a TeamViewer (I have a license) or VNC remote session in a fresh VM.
For sure this is not urgent for me. So, take your time!

Mmh, No Data usually means that our parser had a hickup. I'll look at your examples.

Mmh, No Data usually means that our parser had a hickup. I'll look at your examples.

Hi Andre,

can you hover over the GpgOL Icon and look at the tooltip? Maybe there was an error during validation.

I'm not really sure if "No Key" is a better string for "Ignore Recipient". But most other things are either unclear (ignore recipient) or can be misunderstood like (Do not encrypt to this recipient) as this could also mean that the recipient gets an unencrypted mail.

It now looks like this:

I installed microsoft office 2016 on a brand new laptop and got the same problem described in the post listed above.
My solution was to uninstall the pre-configured app : "Microsoft Office Desktop Apps" and voila!!

I also tested it with Outlook 2010 and there this did not happen. So it's probably save to assume that this was a behavioral change in some more recent Outlook Version.

Has been released and confirmed to be working.

Fix is in, will be released with 3.1.10

Fix is in. Will be released with 3.1.10

This is resolved

It turned out to be a downstream issue and the change in message class was enough from our side.

This is fixed.

This was fixed with 3.1.9

This should be fixed.

Testing with the DGN certificate showed that GPGSM returns a signature verification error (invalid digest algorithm) in this case. So the signature summary is not even checked.

This issues is not really about the CRL's. GpgOL should not activate the EFail protection if a CRL check fails. That is the issue here.

We need to know the issuers of the CRLs under question.

See also T4538 which we can only fix in 2.2 after we have checked that this does not break the VS-NfD approval.