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Are two DNS MX records pointing to the same IP a availability risk as in a single point of failure (SPOF)?

Even if there are three DNS MX records in total for example:

mx1.example.com 192.168.1.1
mx2.example.com 192.168.0.1
mx3.example.com 192.168.0.1
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No.
Taken from Wikipedia (Single point of failure - Wikipeda):

A single point of failure (SPOF) is a part of a system that, if it fails, will stop the entire system from working. SPOFs are undesirable in any system with a goal of high availability or reliability, be it a business practice, software application, or other industrial system.

Since in your case if the server with the ip 192.168.0.1 shuts down the MX service will still be able to work since it has another backup server (192.168.1.1) this is not a SPOF problem and all is okay.

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Even all your MX records point to a single IP address these records by themselvs are not the single point of failure, because the MX records themselves will not fail.

The single point of failure is instead if you have only a single server managing the mail. And in this case it does not matter if this single server has a single or multiple IP addresses. It also does matter if there is only one or if there are multiple MX records for each of these IP addresses.

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The only single point of failure is your DNS provider is not redundant and it goes down, then your email is down. But most MTA's will keep resending the emails for 24 hours on failures.

If the 2 different IP's you listed are assigned to the same machine - Then you will have a SPOF opportunity.

But having multiple MX records point to the same IP is bad if they are used for outgoing mail, just because your rDNS PTR record will not match the host name. This will cause some email deliver-ability pain at certain ESP.

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