I'm using a valid-real email address and valid registration details.
Did you try several addresses (different providers)?
WHAT IS THE PROBLEM? Why can't I register to my own forum? It looks like a bug...
We changed the validation process some months ago... Maybe you problem is related to such changes, cf. Auge's comment:
Only as a note.
There is a further restriction. filter_var does not support IDN (domain names with non latin chars) because the filter is based on RFC 822 which is from 1982. I don't know if IDN domains are in common use for e-mail-addresses (it's not the case in Germany) but it could possibly break in some countries. Thatswhy we did not switch to filter_var until now.
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