SMIME decrypt failed when e-mail is signed and send from Microsoft Outlook

[urbantrooper]

Infos:

• Used Zammad version: 4.1.0
• Installation method (source, package, …): package
• Operating system: CentOS 7
• Database + version: PostgreSQL 9.2.24
• Elasticsearch version: 7.14
• Browser + version: doesn’t matter

Expected behavior:

• Encrypted and signed e-mails send from Microsoft Outlook should be decrypted with the private key stored under system/integration/smime
  
  

Actual behavior:

• If a customer send an e-mail encryted and signed from Microsoft Outlook (2013, 2016) to zammad, the e-mail can’t be decrypted although the private key is stored
  

  

• If a customer send an e-mail encryted and not signed to zammad, the e-mail will be decrypted

• We have the problem with our users here on site and with our customers

• The strange thing is, emails decrypted and signed from Mozilla Thunderbird are decrypted in zammad without any issues

I learnd, that my problem is no bug, but a technical question (SMIME decrypt failed when e-mail is signed and send from Microsoft Outlook · Issue #3734 · zammad/zammad · GitHub) - so, can anyone give me a hint how to resolve my problem?

[MrGeneration]

Did you ensure the user is using the same certificate you expect the user to use?
In the past mostly the user using wrong certificates was the root cause of this.

If it works with Thunderbird but not Outlook, the main culprit is Outlook.

[user123]

To close this issue - Not working unpack of mail body if decrypted body is in signed-data attachment · Issue #3705 · zammad/zammad · GitHub of course it was a bug.