Nextcloud mail 4.0.7 generates invalid smime signature

[Sergeij2000]

Steps to reproduce

1. Setup mail account and install a SMIME-certificate
2. Send two mails to yourself, select signature for the first and encryption for the second
3. Check mails in different mail clients/apps

Expected behavior

The signature should be valid.

Actual behavior

The signature shows a faulty hash value

Encryptions works

Mail app version

4.0.7

Nextcloud version

30.0.2snap2

Mailserver or service

Hetzner mail.your-server,de

Operating system

Ubuntu 24.04.1 server

PHP engine version

PHP 8.2

Nextcloud memory caching

No response

Web server

Apache (supported)

Database

MySQL

Additional info

No response