In addition to everything else being proposed here, you should seriously consider consulting a DNS-based RBL. It's easy to do, especially in a web-backend context where you're guaranteed to be connected to the internet and to have the sender's IP address.

@/=map{[/./g]}qw/.h_nJ Xapou cets krht ele_ r_ra/;
map{y/X_/\n /;print}map{pop@$_}@/for@/
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