There really isn’t a reliable way to “validate” email addresses other than to try sending email to them.
An email address has two parts, separated by the @ sign: the “local part” and the domain. The domain has to follow the rules of DNS, but there are astonishingly few hard rules for the local part.
A validator can check that the domain resolves — that there’s an A or MX record for it in DNS — but it can’t do much about the part before the @ sign.
Whether the local part is correct or not depends on the actual behavior of the mail server for the domain; which means that, without actually trying to send email to it, it can’t really be tested.
There really isn’t a reliable way to “validate” email addresses other than to try sending email to them.
An email address has two parts, separated by the @ sign: the “local part” and the domain. The domain has to follow the rules of DNS, but there are astonishingly few hard rules for the local part.
A validator can check that the domain resolves — that there’s an
AorMXrecord for it in DNS — but it can’t do much about the part before the @ sign.Whether the local part is correct or not depends on the actual behavior of the mail server for the domain; which means that, without actually trying to send email to it, it can’t really be tested.