First you need ubuntu lamp distribution.

Additionally I've changed mysql with mariadb and install aptitude.

aptitude install exim4-daemon-heavy exim4 mariadb-server clamav dovecot \
dovecot-mysql dovecot-sieve dovecot-managesieved libapache2-mod-wsgi \
libmariadb-client-lgpl-dev libmariadbd-dev libmariadb-client-lgpl-dev-compat \
virtualenv clamav-daemon roundcube roundcube-plugins-extra roundcube-plugins \
spamassassin php-zip

MySQL-python needs mysql_config but is's missing even with libmariadb-client-lgpl-dev-compat! So:
ln -s /usr/bin/mariadb_config /usr/bin/mysql_config

git clone https://github.com/ventricola/exim-dovecot-mysql-mailserver.git <somewhare>

a2enmod ssl
a2enconf django-wsgi.conf
a2enconf postmaster.conf

Edit what necessary. At least replace fakedomain.tld everywhere proper domain name. Put everything in place. I use /var/www/html for mailctl.

Generate certs:
openssl genrsa -out /etc/exim4/dkim.fakedomain.tld.key 2048
openssl rsa -in /etc/exim4/dkim.fakedomain.tld.key -pubout -out /etc/exim4/dkim.fakedomain.tld.crt

Add DNS records like:

fakedomain.tld. IN TXT "v=spf1 mx a ip4:1.1.1.1/32 include:_spf.google.com ?all"
dkim._domainkey.fakedomain.tld. IN TXT "k=rsa; p=MIIBIjA...DAQAB"
_dmarc.fakedomain.tld. 899 IN TXT "v=DMARC1; p=none; sp=none; rua=mailto:[email protected] fo=1"

Cd to mailctl activate virtualenv or ever reinstall it first, then reinstall requirements.
pip uninstall -r requirements.txt
pip install -r requirements.txt