If you process mail on a different server from where the RT web interface is installed, you can install the mailgate only.

(The following dialog was recorded with version 3.4.4.)

Extract tarball and configure.

# cd /usr/local/src
# wget http://download.bestpractical.com/pub/rt/release/rt-3.4.4.tar.gz
[...]
# gunzip rt-3.4.4.tar.gz
# tar xf rt-3.4.4.tar.gz
# cd rt-3.4.4
# ./configure --prefix=/usr/local
[...]
#

See what dependencies you are missing. If any are missing in the MAILGATE section, install the required packages.

# make testdeps
perl:
      5.8.3...found
[...]
MAILGATE dependencies:
      HTML::TreeBuilder ...found
      HTML::FormatText ...found
      Getopt::Long ...found
      LWP::UserAgent ...found
[...]

Copy the rt-mailgate file from the ${prefix}/bin dir on the other machine where you installed RT and put in your bin dir (e.g., /usr/local/bin/rt-mailgate).

-- MarkBucciarelli, November 15, 2006