Who does this, i.e. deleting email from server, during a vacation? :-) It doesn’t even sound like a good excuse! it should be a super long vacation and I am pretty sure no company does this “deletion policy”.

As an alternative, I would be sincere instead, saying something like this: “Thank you for your email! I am currently on vacation, so will not access my email until my return to office on the […]. I would appreciate if your could send a reminder after my return date to ensure that I won’t miss your request. For any urgent matters, please contact my stand-in […] or my manager […].”

It could be very possible that they won’t send a reminder because the issue was solved in the meantime.