SendmailAnalyzer:
As is name suggest is a free Sendmail/Postfix log analyzer. It process maillog files and generate dynamic statistics in HTML and graphical output. The reports are generated in real time so that it let you know at any moment what is going on your mail servers. It use time (hour, day, month and year views) and cross-linked navigation for easy use. SendmailAnalyzer is easy to install and highly configurable to match the dozen of Sendmail possible configurations. It also support report for all the major milter or sendmail filters like SpamAssassin, MailScanner, Clamav, Amavis, RBL check, J-ChkMail, etc. SendmailAnalyzer is really helpful for IT reporting.
http://sareport.darold.net
Swaks:
is a featureful, flexible, scriptable, transaction-oriented SMTP test tool written and maintained by John Jetmore. Features include:
SMTP extensions including TLS, authentication, pipelining, and XCLIENT
Protocols including SMTP, ESMTP, and LMTP
Transports including unix-domain sockets, internet-domain sockets (IPv4 and IPv6), and pipes to spawned processes
Completely scriptable configuration, with option specification via environment variables, configuration files, and command line
http://www.jetmore.org/john/code/swaks