apt-get install python3-imaplib

useradd modoboa
su modoboa

mkdir venv_2.0.0-beta.3
python3 -m venv ./venv_2.0.0-beta.3
source ./venv_2.0.0-beta.3/bin/activate
pip install psycopg2-binary
> pip install psycopg2-binary==2.8.6
pip install "git+https//github.com/modoboa/modoboa.git@2.0.0-beta.3#modoboa"
pip install modoboa-sievefilters
pip install modoboa-stats
# create user modoboa and give the rights to mail database
modoboa-admin.py deploy instance --collectstatic --domain listonmail.fr --dburl default:postgres://modoboa:modoboa_password@127.0.0.1:5432/mail

# fill the crontab with the good variables

# add the nginx/apache2 configuration

# add the uwsgi configuration

# configure uwsgi settings

https://github.com/modoboa/modoboa-webmail/issues/227#issuecomment-1003763831