There are many reasons why you might want to have your own SMTP server. But there are also many reasons why lots of businesses outsource email sending to third party services. One of the big problems with having your own SMTP server is that it is quite hard to set the whole thing up to get a solid delivery rate. What does it mean? It means that if you just naively install an SMTP server and try to send emails through it, many of your emails will not be delivered. Moreover, you will not even know that your emails did not reach their recipients. If you have decided that you want your own SMTP server, this article will help you reach a solid delivery rate – i.e. your emails will be delivered to existing mail boxes and will not get deleted as spam. If something is not configured perfectly, your emails can be lost completely without a notice, moved to Junk folders, or not accepted for a delivery. So, if you are asking following questions: How to deliver an email? How to setup MX server? How to increase the delivery rate? Just keep reading.
Note that the methods described in this article will work for you only if you are a legitimate business and do not intend to send spam. If you do send spam, it is a good thing that your emails are not delivered, and even if you set everything properly, many of your mails will get deleted.
This article only discusses sending emails. Receiving emails with your own mail server is another wide topic. We will use the term mail server universally for all roles and names such as mail exchanger, MX host, MTA (mail transfer agent), or mail relay.