I would recommend checking out these two articles:

• Some generic information regarding running your own mail server:

https://www.digitalocean.com/community/tutorials/why-you-may-not-want-to-run-your-own-mail-server

• How to setup your email server:

https://www.digitalocean.com/community/tutorials/how-to-set-up-a-postfix-e-mail-server-with-dovecot

Of course you need to make sure that you are sending out emails to legitimate subscribers otherwise your account might be disabled if you try to send out spam.