debian: apt-get install sendmail

One thing to note, if you add FEATURE(access_db') to your sendmail.mc, you will need to create your /etc/mail/access file, then run ****make**** once, which will modify the makefile to add rules for the access file. Then, run ****make**** a second time, and it will create the /etc/mail/access.db file from /etc/mail/access - I use this along with FEATURE(blacklist_recipients') for spamtrap addresses, like:

spamtrap@example.com 553 Only a spammer would send to this address

Once the database has been created, you only need to run the makefile once each time you add an entry to the access file.

The self-modifying makefile also works with /etc/mail/virtusertable if you want to use a virtual user table. I use the virtual user table to allow any address at my domain to work, getting forwarded to me; this basically gives me a honeypot, and I can blacklist any address that gets spammed. So far, the only spam hits I've received have been to spamtrap addresses that I've used on USENET posts, which get 553'd before I ever see them.