yum search command provides a package listing with results of the search by pattern matching in the description, summary and package name. Let us see an example:
$ su -c "yum search imap"
...
================================ Matched: imap =================================
cyrus-imapd.x86_64 : A high-performance mail server with IMAP, POP3, NNTP and
: SIEVE support
cyrus-imapd-devel.i686 : Cyrus IMAP server development files
cyrus-imapd-devel.x86_64 : Cyrus IMAP server development files
cyrus-imapd-utils.x86_64 : Cyrus IMAP server administration utilities
imapfilter.x86_64 : A flexible client side mail filtering utility for IMAP
: servers
imapsync.noarch : Tool to migrate email between IMAP servers
...
...
...
squirrelmail.noarch : webmail client written in php
stunnel.x86_64 : An SSL-encrypting socket wrapper
tcpjunk.x86_64 : TCP protocols testing tool
wammu.noarch : Mobile Phone Manager - Gammu GUI
xfce4-mailwatch-plugin.x86_64 : Mail Watcher plugin for the Xfce panel
zarafa.x86_64 : Open Source Edition of the Zarafa Collaboration Platform