Postfix : error: unsupported dictionary type: mysql

Solution 1:

[SOLVED] This fixed the issue for me in Ubuntu 14.04:

sudo apt-get install postfix-mysql

Solution 2:

1. Check output of postconf -m. It will look like this:

   root@ds94:/usr/local/etc/postfix # postconf -m
   btree
   cidr
   environ
   fail
   hash
   internal
   memcache
   mysql
   pcre
   proxy
   regexp
   socketmap
   static
   tcp
   texthash
   unix
   

2. If in output of postconf there isn't mysql string, it means that postfix is built without mysql support. To resolve it install postfix-mysql package.