Following a guide to setup a basic email service is quite easy to do, but after a while the lack of proper implementation and maintenance of the standards will start to cause deliverability issues. Those are frustrating and most end up writing a long rant on why Google is evil because their email ended up in spam. When in fact, it usually is a misconfiguration, but those can be really hard to detect.
IMO there is still great satisfaction in running any internet service yourself. But, if you rely on this service to work, it just no longer makes financial sense to do so.
It takes resources to keep any internet service running correctly. Even the simple stuff can quickly get overlooked, I have seen so many self-hosted email servers that have expired certificates (like with the domain of the OP) or lack support for any of the modern security extensions such as DMARC or MTA-STS.
For most businesses my recommendation is not to run it yourself. Like you wouldn't run your own DNS service anymore. Of course it can be done, and in some cases it makes sense to run stuff yourself (usually when operating at a very large scale). But it almost always makes more financial sense to use a hosted email solution.
We haven't written a guide (yet) on setting up an email server with all the bells and whistles. But if you want to read more on all the email security standards, have a look here: https://www.mailhardener.com/kb/