I am new to sendmail and just started on Perl. This might be a really basic question, since I know very
little about sendmail or perl, if anyone can help me it would be greatly appreciated.

I will try to be thorough in my explaination... Here's the problem:

I have an email address userlist@dummy.com and have a lists of emaill addresses in a MySQL database (a mailing list).
if a message is sent to the userlists email address, I want a perl script to be executed
that pulls in the list details from a MySQL database, and forwards the message to all the
emails addresses in the list.

Also I wondered if address extensions are possible with sendmail.I mean I wanted to maintain multiple lists
in the database, if a message is recieved with an address like userlists-1678@dummy.com. I want to pull the
email address for mailinglist_id 1679 from the database and forward the email to the users in the list.

I am ok with perl programming and can handel the database part of pulling the mailing list etc...
but I'm not at all sure on the SendMail configuration part. My questions are

1) How can I configure sendmail to run a perl script when an email is recieved at userlist@dummy.com?
2) How can I take the message from send mail and forward the message to addresses that I pull from the database?
3) Are Address extensions possible in SendMail, if yes then how do I enable that?
4) Can I strip the id (1678 from the address like userlists-1678@dummy.com) so that I can use that to query the database for the appropriate list.

I'd really appreciate any help in this regards. Thanks in Advance

Well why not just the SmarterMail List server for your needs? HostMySite offers a free 5,000 messages per month list server for free with their hosting accounts. It seems it would be easier to use the built in abilites of that than to write code for something someone else has already figured out .

You may even want to check out their support page for the list at http://hostmysite.com/support/list-server/ so you can find out if it is going to meet your needs. Or perhaps incorporate it into what you are trying to do with the scripts..