Hi Martijn,

I investigated in this case just once more.

My email client understands S/MIME as long ciphermail is offline and not decrypting opaquely encrypted Mails. So if I send encrypted and signed mails from Outlook directly into my inbox, everything is fine. Only if Ciphermail is decrypting, my email client can't read the mail anymore.

Do you see a chance for upcoming versions of Ciphermail to decrypt opaquely encrypted signed mails into clear text signed mails or give somehow the configuration option?

Best regards,

Andreas

-----Ursprüngliche Nachricht-----
Von: Martijn Brinkers via Users <users@lists.ciphermail.com>
Gesendet: Mittwoch 24. Februar 2021 10:56
An: users@lists.ciphermail.com
CC: Andreas Studenski <ciphermail@webcoding24.com>; Martijn Brinkers <martijn@ciphermail.com>
Betreff: [CipherMail User] Re: S/MIME message has been decrypted but sending encrypted!

Hi Andreas,

My guess is that the emails are not encrypted by opaque signed. S/MIME
signing supports two types of encoding: clear text and opaque. With
opaque signed email you need a mail client which understands S/MIME
signed email. Unfortunately some email clients like for example Outlook
use opaque signing when the email is encrypted. After decryption the
resulting email is therefore opaquely signed. If you mail client does
not support S/MIME you will only see an attachment names smime.p7m.

You can configure the gateway to remove the signature by enabling the
S/MIME advanced setting "Remove signature". This will then convert the
smime.p7m attachment to a normal email.

Unfortunately at the moment this will remove the signature from all
S/MIME emails, i.e., also from the clear signed emails and not just
from the opaque signed emails.

Kind regards,

Martijn Brinkers

-- 
CipherMail email encryption
Email encryption with support for S/MIME,
OpenPGP, PDF Messenger and Webmail Messenger

On Wed, 2021-02-24 at 09:48 +0000, Andreas Studenski via Users wrote:
> Hi there,
> 
> my problem exists for a longer period now. As more and more S/MIME
> crypted mails are incoming, situation is getting annoying.
> So I started solving the problem, unfortunately without success.
> 
> I have internal domains (locality "internal") in ciphermail, S/MIME
> certficates including private keys are successfully imported, mail
> routing works, everything is running fine except one weird thing:
> 
> When S/MIME crypted mails are incoming for my user they will be
> decrypted by ciphermail. Logfile is showing "S/MIME message has been
> decrypted." and "S/MIME signature was valid", but only crypted mails
> are arriving in my inbox.
> I have searched for ages now and checked the configuration many
> times. Also reinstalled the server. Problem stays the same.
> Ciphermail does not decrypt mails.
> 
> Anybody knowing this problem?
> Many thanks in advance.
> 
> Andreas