Error in email validation specs?

[Lucas Malor]

Hello all. In your validation rules for email inputs, you say the local part can be long as you want. But the SMTP spec, RFC 5321 4.5.3.1.1, says that it must be 64 chars long at maximum. RFT 5322 3.4.1 doesn't specify the length of local part, but I think it implicitly follow what specified by RFC 5321 (even if it says explicitly to follow RFC 5321 for the domain part...)

[Lucas Malor]

I've found some another little errors: each label of an hostname must be long at maximum 63 characters (RFC 1034 #3.1), and it can't start or end with an hyphen (RFC 952, under "Assumptions", modified by RFC 1123 #2). Furthermore the entire length of an email address can't exceed 256 characters: RFC 5321 #4.5.3.1.3

I read all these informations from Wikipedia articles about email address and hostname syntax, but I verified them as you can read.

[zcorpan]

https://www.w3.org/Bugs/Public/show_bug.cgi?id=21617

[Lucas Malor]

Thank you for the reply. I strongly disagree with ignoring the length constraints of RFCs. I think they are practical enough for the real use, even if applied to punyencoded strings.