¿Que versión de Sendmail tengo?

Which sendmail version do I run?
To find out which version of sendmail is installed on your system, you can try the following commands:

sendmail -d0.4 -bv root
should tell you its version and some basic settings.

telnet localhost 25
sendmail should greet you with its welcome message and tell you the version of its binary and config file. Enter QUIT to leave this mode.

Fuente: http://www.sendmail.org/~ca/email/lfaq.html