25-10-22 10:14 AM
25-10-22 11:40 AM
Hello @Tushigbayar Tseveenbayar,
The smime.p7s attachment is a digital signature certificate. It is not an encrypted PDF.
Are there other attachments on your email?
Cheers,
25-10-22 11:48 AM
25-10-22 12:27 PM
Based on this Google help page it seems there's not really anything you need to do, from an API perspective, to handle S/MIME encrypted content. The GMail system should handle it automatically assuming it's properly configured between the sender and receiver (i.e. keys have been exchanged).
https://support.google.com/a/answer/6374496?hl=en#zippy=%2Cstep-upload-certificates%2Cstep-have-users-exchange-keys
I'd suggest touching base with your Google Workspace administrator to verify your S/MIME configuration.
Cheers,