Introducing Sendmail

Sendmail is a general purpose email routing facility that supports many kinds of mail transfer and delivery methods, most notably the Simple Mail Transfer Protocol (SMTP) used for transporting email over the internet. Other mail transport protocols supported by sendmail include ESMTP, mail11, Hylafax, Quickpage and UUCP.

Sendmail is a well known project of the open source software community and its official home page can be found at www.sendmail.org where you can download the latest source distributions, catch up on the latest Sendmail news and read the latest security advisories related to sendmail. There is an excellent FAQ in the support section of the Sendmail website that covers many of the commonly asked questions. If you are running into a problem that isnt covered in the fAQ then consider asking questions in the Sendmail newsgroup, comp.mail.sendmail. Include as much information as you can about your problem including platform and the sendmail version and many of the more experienced hands in the newsgroup will be more than happy to help. Bear in mind when posting in the newsgroup that the people who answer your posts are end users just like yourself.

Sendmail is a derivative of the ARPANET Delivermail program written by Eric Allman that shipped in 1979 with BSD 4.0 and 4.1. Eric wrote Sendmail in the early 1980's as Delivermail's successor and it first appeared with BSD 4.1c in 1983. Sendmail has evolved to be the most popular mail transport agent on the internet, its popularity strengthened by its position as the standard MTA for most Unix-like operating systems, including Linux.

Chances are fairly high that the Linux distribution you have selected uses Sendmail as its mail transport agent. If it is already installed on your Linux server then it is unlikely it will need to be reinstalled, simply configure it, add your users and you are ready to go. If you need to add additional functionality such as spam control you may need to build a new sendmail.cf, the key file that is changed to alter Sendmails default behaviour. Standard configuration packages delivered with the source code distribution such as the sendmail.cf file require the use of the M4 macro language which hides much of the configuration complexity, sendmail.cf should never be directly edited.