Microsoft exchange server 2010 : unleashed / Rand Morimoto...[et al.]
Mastering microsoft exchange server 2007 / Barry Gerber, Jim McBee
Microsoft exchange server 2007 : implementation and administration / Jim McBee, Benjamin Craig
Microsoft exchange server 2007 : administrator's companion / Walter Glenn, Scott Lowe and Joshua Maher
Sendmail / Bryan Costales, Eric Allman
MH & xmh : e-mail for users and programmers / Jerry D. Peek