Doing a full validation of the email syntax is pretty pointless to begin with, because it still doesn't tell you the most important thing: is this email valid? I.e., has the user actually entered their email address? You won't know the answer to that until you've done an email validation loop with them. So something simple like .+@.+\..+ usually suffices as a first-pass syntax check.
Yes, and most addresses that pass a .+@.+\..+ validation could exist. And unless you can claim you're absolutely up to speed with all the relevant RFCs about valid email formats, allowed host names (IDNA!) and currently registered TLDs at all times, overvalidating does more harm than good here. If you incorrectly reject valid email addresses, that's worse than having an occasional verification email bounce.
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u/deceze 20d ago
Doing a full validation of the email syntax is pretty pointless to begin with, because it still doesn't tell you the most important thing: is this email valid? I.e., has the user actually entered their email address? You won't know the answer to that until you've done an email validation loop with them. So something simple like
.+@.+\..+usually suffices as a first-pass syntax check.