Upgrade and downgrade instructions
To upgrade MailerQ from version < 5.7 to 5.7+
Debian/Ubuntu:
sudo apt update
sudo apt install -y mailerq
sudo mailerq --repair-database
CentOS/RHEL:
yum update
mailerq --repair-database
To downgrade MailerQ from version 5.7+ to 5.6
Debian/Ubuntu:
sudo apt-get install -y --allow-downgrades mailerq-5.6
sudo mailerq --repair-database
CentOS/RHEL:
yum remove mailerq-5.7
yum install mailerq-5.6
mailerq --repair-database