Postfix

https://help.ubuntu.com/community/Postfix

Packages

root@weasel:/var/log# dpkg -l *postfix*
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Installed/Config-f/Unpacked/Failed-cfg/Half-inst/t-aWait/T-pend
|/ Err?=(none)/Hold/Reinst-required/X=both-problems (Status,Err: uppercase=bad)
||/ Name                       Version                    Description
+++-==========================-==========================-====================================================================
ii  postfix                    2.5.1-2ubuntu1             High-performance mail transport agent


Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Installed/Config-f/Unpacked/Failed-cfg/Half-inst/t-aWait/T-pend
|/ Err?=(none)/Hold/Reinst-required/X=both-problems (Status,Err: uppercase=bad)
||/ Name                       Version                    Description
+++-==========================-==========================-====================================================================
pn  libsasl2                   <none>                     (no description available)
ii  libsasl2-2                 2.1.22.dfsg1-18ubuntu2     Cyrus SASL - authentication abstraction library
ii  libsasl2-modules           2.1.22.dfsg1-18ubuntu2     Cyrus SASL - pluggable authentication modules
ii  sasl2-bin                  2.1.22.dfsg1-18ubuntu2     Cyrus SASL - administration programs for SASL users database