|Lesson 6||Compiling sendmail |
|Objective|| Explain how to compile sendmail.|
Linux and Solaris are distributed with current versions of
already installed. However, you may need to upgrade your version of
sendmail to keep up with security fixes and improvements.
sendmail, you download the appropriate archive file from
proofpoint.com and unpack the archive using
uncompress or gunzip compression utilities, together with
Versions 8.9 and higher of
sendmail include a script file named Build. You execute this file by using the
sh command to compile a new version of
sendmail. Build automatically detects your operating system type, then builds
sendmail accordingly. Once you have compiled the program, you must create a new sendmail.cf file, then kill any current running
version and start the new one. Then you can troubleshoot the new installation.
sendmail program may have specific problems with some UNIX flavors. For example, if your system uses gcc 2.4.x or 2.5.x, you cannot use the
–O (optimization) argument. If you have trouble compiling
sendmail, consult the
site or the
sendmail newsgroup. See the Internet Resources section of the course Resources page for these links.
sendmail file locations
sendmail traditionally stores its configuration files in the /etc directory. These include the main configuration file sendmail.cf, along with supporting configuration information such as the aliases file.
The /etc/mail directory contains other support files, including files controlling access to the
sendmail process, such as the ip_allow, ip_deny, and relay_allow files.
The precise locations of
sendmail configuration files can vary depending on the UNIX version. For example, HP-UX and Solaris put their alias file in the /etc/mail/aliases directory, whereas Irix uses /etc/aliases.
sendmail configuration is being standardized and all UNIX flavors should use /etc/mail as the directory for all
sendmail configuration files. All subsequent iterations of
sendmail will use this location by default.
sendmail and BIND (DNS)
You must have properly configured DNS to run
sendmail. If you plan to receive email at your site, you must make modifications to your
DNS zone files to enable remote SMTP servers to find you. We will discuss the interaction between DNS and SMTP in a later lesson.