Какая будет максимально допустимая длина (вообщем) для мыла, если через FILTER_VALIDATE_EMAIL проверять ?
The maximum length of an email address is 254 characters Every email address is composed of two parts. The local part comes before the '@' sign, and the domain part follows it. In "user@example.com", the local part is "user", and the domain part is "example.com". The local part must not exceed 64 characters and the domain part cannot be longer than 255 characters; the total combined length of all characters (including '@' and punctuation) must not exceed 254 characters, however.
Длина не 255 символов, а меньше я проверял, а сколько не знаю(( влом считать символы эта инфа устарела