apt-get substitute MariaDB in place of MySQL

I am trying to install postfixadmin on Ubuntu. I have MariaDB installed and want to use that as my MySQL database. However, the package dependencies for postfixadmin are MySQL, not MariaDB. Is there any way I can tell apt to ignore the need for MySQL (and remember this permanently for any upgrades) and use MariaDB instead? Or am I going to be stuck and need to build postfixadmin instead?

Edit: This is what apt wants to do...

sudo apt-get install -s postfixadmin 
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following additional packages will be installed:
  apache2 apache2-bin apache2-data apache2-utils dbconfig-common dovecot-core libapache2-mod-php5 libapr1 libaprutil1 libaprutil1-dbd-sqlite3 libaprutil1-ldap

  libexttextcat-2.0-0 libexttextcat-data liblockfile-bin liblockfile1 liblua5.1-0 lockfile-progs mysql-client mysql-client-5.6 mysql-client-core-5.6 mysql-server
  mysql-server-5.6 mysql-server-core-5.6 ntpdate php5-mysql postfix-mysql wwwconfig-common
Suggested packages:
  apache2-doc apache2-suexec-pristine | apache2-suexec-custom dbconfig-mysql | dbconfig-pgsql | dbconfig-sqlite | dbconfig-sqlite3 | dbconfig-no-thanks dovecot-gssapi
  dovecot-sieve dovecot-pgsql dovecot-mysql dovecot-sqlite dovecot-ldap dovecot-imapd dovecot-pop3d dovecot-lmtpd dovecot-managesieved dovecot-solr dovecot-lucene mailx tinyca
  postgresql-client
Recommended packages:
  zendframework
The following packages will be REMOVED
  mariadb-client mariadb-client-10.0 mariadb-client-core-10.0 mariadb-server mariadb-server-10.0 mariadb-server-core-10.0

The following NEW packages will be installed
  apache2 apache2-bin apache2-data apache2-utils dbconfig-common dovecot-core libapache2-mod-php5 libapr1 libaprutil1 libaprutil1-dbd-sqlite3 libaprutil1-ldap
  libexttextcat-2.0-0 libexttextcat-data liblockfile-bin liblockfile1 liblua5.1-0 lockfile-progs mysql-client mysql-client-5.6 mysql-client-core-5.6 mysql-server
  mysql-server-5.6 mysql-server-core-5.6 ntpdate php5-mysql postfix-mysql postfixadmin wwwconfig-common
0 to upgrade, 28 to newly install, 6 to remove and 50 not to upgrade.

postfixadmin should work with MariaDB. It is a drop-in replacement. In $CONF[database_type] you would need to to configure 'mysql' or 'mysqli' and not 'mariadb'.

if postfixadmin keeps trying to install MySql you can try the --nodeps flag with apt-get or download and install the package using dpkg with the option --ignore-depends

Good luck!