Today I have received an interesting question. Coming from an Exchange background I thought it might be a Lotus specific item and of course stated I had no answer to this question.
Now, that said let’s see some of your thoughts on this question:
“What is the maximum number of MX records you can have?”
Here is my thought on this:
Honestly there is a theoretical limit of 10 in IPv4 and a payload of 65507 bytes where IPv6 is 65527 bytes. Anything larger results in IP fragmentation; definitely bad for email. That said why would you do more than 4-5 MX records to begin with? That is a theoretical limit, not an actual published limit.
It has definitely lead to many internal interesting discussions today with several other engineers.