DiY

Troubleshooting FAQ

http://www.milter.info/milter-siq/

http://www.milter.info/milter-ahead/

http://sendmail.org/

Some resources for How to configure Sendmail as a gateway

http://www.google.com/search?hl=en&ie=UTF-8&q=configure+sendmail+gateway&btnG=Google+Search

*nix / Sendmail expert consultants are also available: http://outboundindex.org/dell/#4hire