We are experiencing problems sending to a client who are using cloud Symatec Endpoint service for their mail server are recieving the above message. When we send to other mail servers, there are no issues with PGP.
The message we are sending is generated in c#. We notice that if we send via outlook it does not have this problem. Obviously the service is a little more fussy about the format of the email which we are obviously sending incorrectly.
The email the client is seeing from symantec shows the email has decrypted ok but no attached certificate (p7s), just the file attached to the email. Now at the bottom it does state our company name as the issuer (which must have come from the p7s) so it is obviously reading the signing certificate. The client has found Symantec struggles to find the correct certificate when more than one certificate is upload with the same Issuer E value. The question here, is it finding certificates based on the issuer E property or the Subject E property? Our certifciate has only one certifcate in the chain/path.
Has anyone got any ideas about how to identify what Symantec is objecting to? Is there any logs to say which certificate it has picked up and compared it to? How do we see the signing certificate attached to the email?