I’ll go over these one by one below:
”I see what you are saying but surely Secure Email should be developed to be compatible with the majority of AV’s that have virus detection for mail and not solely for in-house developed software.”
SecureEmail is a client based application. It encrypts email on the client before it travels to the server (over SMTP, and decryption for POP3 and IMAP).
CSE encrypt the e-mails using S/MIME, just after they leave the e-mail client, in the client PC’s network stack. It’s also possible to encrypt e-mails using Outlook’s and Thunderbird’s S/MIME features, which encrypt in the e-mail client before even entering the network stack, like this
Outlook/Thunderbird ← Outlook TB Encrypt here
ComoeoSecureEmail ← CSE encrypt here, if not already encrypted
MailServer ← Server based AV.
If your client based AV encrypts using a mail client plug-in it will probably scan before the mail leaves the mail client. This can obviously only be done for mail clients where plug-ins are possible and the mail client supplies enough functionality, which are few. If you encrypt your mail on your client PC then any server AV will have problems decrypting it and scanning it. There are a great deal of reason to encrypt at the client and not on a server gateway, especially to allow full journey encryption. Here’s a good report to look at to which gives a number of reasons why:
In the future CSE enterprises edition will have a feature set rich enough to allow the server to decrypt the mail and scan for viruses etc but this requires a server component that is user private key aware. SE will supply a large number of configurations to suit the needs of each particular enterprise.
”I assume Avast Mail Server is Network based too as it sits monitoring the ports. I am not saying that it is a Secure Email problem, “
You are correct, it’s actually a point of AV detection problem. By the very nature of encrypting something you are hiding and securing it, the whole point of the exercise. This also ensure the mail cannot be edited and the contents are indeed what was intended by the sender.
“it may well be a problem with Avast. I was asking the question to try and attain a better understanding of the way it worked and highlight a possible compatibility issue.”
Comodo SE tries to position itself in client the LSP network stack after all AV but this is not guaranteed (for Windows technical reasons) and installing an AV with network monitoring such as LSP, after SE may cause AV to be carried out after SE has encrypted the data. By the way, if you take SE out of the equation completely and encrypt using Thunderbird or Outlook, then a network monitoring AV will have no chance to scan the e-mails anyway.
It’s really a question of network topology and client software topology. You really need an AV with a client plug-in if you are encrypting with Outlook/TB alone, the same applies to SE but in a slightly lesser extent.
Hope this helps