Since you already removed them, that step is not needed.
Also, since you use a MDR catch to the admin, they will end up in there too, and that can get huge.
But, again, DISABLE NDR to the internet, it is useless and confirms spammers your email addresses.
How? They send to random addresses, those returning an NDR are dismissed but thos which do NOT send an NDR, exist, and then the spamming begins.
If the NDR's come from legit contacts, it is of course your duty to notify them.
Other senders (junk etc.) just block them.
Marc
If 'something' 'somewhere' gives 'some' error, expect random guesses or no replies at all. Please specify details.
Free Tip: The F1 Key does NOT destroy your PC!