Mailing List Message #106774
From: Gib Henry <>
Subject: SSL/TLS Cert works in clients, but not in CGP
Date: Sun, 4 Mar 2018 20:13:08 -0600
To: CommuniGate Pro Discussions <>

I have an S/MIME certificate which works fine for signing, encrypting, and decrypting email with Mac OS and iOS devices via CGP (this list won’t accept signed email).  I installed it into CGP 6.1.19 via webmail Settings/Secure Mail (it’s also installed in the browser used).  When I send encrypted email via CGP webmail or Pronto, the recipient email clients cannot read it: 

  • iOS Mail says “This message is encrypted.  Install a profile containing your encryption identity to decrypt this message.”  (The same certificate is installed—the serial numbers and dates match!)
  • Thunderbird says: “The sender encrypted this message to you using one of your digital certificates, however Thunderbird was not able to find this certificate and corresponding private key.”  (Again, it is installed in Thunderbird, and the serial numbers and dates match.)
  • CGP Webmail and Pronto both can unlock and display the email’s encrypted text, but flag the signature in red:  “Content Unaltered as verified By:  presented certificate is issued by an unknown authority: <>”.  Curiously, the issuing authority is the same one that issued the domain SSL certificate (Comodo).  They’re all current.
  • Mac OS and iOS devices also cannot read the CGP-originated copy in Sent Items, but CGP webmail and Pronto can.
  • Email sent from me to me in Thunderbird is decrypted and readable in both T’bird and CGP; the reply from CGP is not readable in T’bird.
  • Email only signed from CGP shows as validly signed in Thunderbird, so evidently the certificate is working correctly.

I have uninstalled and reinstalled twice, and have ensured that the Comodo chain is complete.

Two questions: 

  1. Is this problem more likely to lie with CGP, or elsewhere? 
  2. If it’s my key, and it’s installed, why can’t the email client find it in messages via webmail and Pronto, but can find it in messages via other iOS and Mac OS clients?

Thanks in advance for any insight you can offer.  Cheers,

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