I just purchased VPS from DigitalOcean and installed LAMP but stuck at mail server. We get 5000+ visits/day and we do sent newsletters to our 10000+ subscribers 2 to 3 times a week and want about 20+ emails for the team members. So is it good to install mail server on the same machine which serves website. Is it cause overload on server ? Do i need to buy two droplets for mail server and web server? I am newbie to VPS and don't know how to install mail server. Else is it better to go for managed VPS.
Please guide me in right direction.