I’d assume that to be true for the reason that sub-addressing is a thing and ESPs use all sorts of separators e.g. some use
+ while others use
So in that sense, if some provider uses
- to allow for sub-addressing emails then screening at discourse stands true.
email@example.com is blocked but
firstname.lastname@example.org is not then
email@example.com can still register by just adding a
+new to their existing email. That defeats the purpose of screening.
So it seems like by design but I’d have a look into the code for an evidence verifying the same.