We have had a brief look at sendmail . The world of sendmail is vast. Most sendmail administrators find themselves consumed by the sendmail.cf file. If sendmail tickles your fancy, I urge you to read the O'Reilly book listed in the references. You should also keep an eye on the excellent web site http://www.sendmail.org for recent releases, bugs , and fixes. Even though our time with sendmail has been short, we have enabled some interesting features of the software, including dealing with spamming . I hope that this section will give you the confidence to explore the world of sendmail a little further.