Xplico is an open source Network Forensic Analysis Tool (NFAT) that allows for data extraction from traffic captures. It supports extraction of mail from POP, IMAP, and SMTP, can extract VoIP streams, etc.
You can download it from the following link: https://packetstormsecurity.com/files/download/72197/xplico-0.1_deft4.tgz
Source: https://packetstormsecurity.com/files/72197/xplico-0.1_deft4.tgz.html