Advanced Perl Programming, by Sriram
Srinivasan (O'Reilly, 1997) has a good section on programming
network servers.
Effective Perl Programming, by Joseph Hall with
Randal Schwartz (Addison Wesley, 1998) is a useful book for picking
up Perl idioms.
http://www.cauce.org/ is a site
from Coalition Against Unsolicited Email. There are many sites
devoted to fighting Unsolicited Commercial Email; this site is a good
place to start. It has pointers to many other sites, including those
that go into greater detail about the analysis of mail headers for
this process.
http://www.eudora.com/developers/scripting.html
contains information for scripting Eudora with pointers to other
AppleScript references.
http://www.microsoft.com and
http://msdn.microsoft.com
have information on "MAPI," "active
messaging," and "CDO." The name of this technology has changed twice so far, so
I'm hesitant to give you a specific pointer. There is plenty of
good information at the Microsoft sites (especially in the MSDN
library section) on these topics, but it tends to move around a bit.
Perl Cookbook, by Tom
Christiansen and Nathan Torkington (O'Reilly, 1998), also
addresses the programming of network servers.
RFC821:Simple Mail Transfer Protocol, J.
Postel, 1982.
RFC822:Standard for the format of ARPA Internet text
messages, D. Crocker, 1982.
RFC954:NICNAME/WHOIS, K. Harrenstien, M.
Stahl, and E. Feinler, 1985.