gpgmailencrypt can encrypt e-mails and check for spam and viruses.

It supports

• PGP/Inline
• PGP/Mime
• S/Mime
• PDF

For spam checking it supports

• spamassassin
• bogofilter

For virus checking it supports

• avast
• bitdefender
• clamav
• drweb
• f-prot
• sophos

It can be used normally as a script doing everything on command line, in daemon mode, where gpgmailencrypt acts as an encrypting smtp server or as a module for programmers.

It takes e-mails and returns the e-mail encrypted to another e-mail server if a encryption key exists for the receiver. Otherwise it returns the e-mail unencrypted. The encryption method can be selected per user.

See gpgmailencrypt documentation.pdf for more info.(https://github.com/gpgmailencrypt/gpgmailencrypt/blob/master/documentation/gpgmailencrypt%20documentation.pdf)