@BRRABill said in Backup MX or no?:
So, to answer the question posted about that article, if you are interested in making sure your e-mail gets delivered, then ignore that article.
The article is fine, you just have to read it to see the context. This is the context setting piece:
They do this as secondary records usually point to email servers that deploy little or no security checks such as those you’d find at some ISP’s for example. This encourages the spamming servers to keep sending even more as they can see it’s being accepted and so the vicious circle continues.
Basically we see people seeing up a second MX and not maintaining it.
So instead of telling people to get a clue and manage their servers, they say to just do things poorly. It's more of "we assume that you won't take good advice, so we'll give you more bad advice based on that assumption."
If you truly assume that you simply won't properly maintain the second SMTP MTA, then sure, don't have one. But that applies at a much more general level. Let me provide a best practice that supersedes all of this:
Best Practice: Never run a server or IT resource that you do not properly maintain.
