After I had ran the docker-compose up -d command, I was presented with the restya board login.
After setting up everything (users, boards, change default passwords) I was not getting notifications through email,
I checked and the postfix service was not working correctly.
Here is what I did to fix it,
I went and removed the file master.pid from /var/spool/postfix/pid
Then I did a service postfix start.