There is no point. Even if you can verify that the email address is syntactically valid, you’ll still need to check that it was not mistyped, and that it actually goes to the person you think it does. The only way to do that is to send them an email and have them click a … Read more
The easiest and safest way to check whether an email address is well-formed is to use the filter_var() function: if (!filter_var($email, FILTER_VALIDATE_EMAIL)) { // invalid emailaddress } Additionally you can check whether the domain defines an MX record: if (!checkdnsrr($domain, ‘MX’)) { // domain is not valid } But this still doesn’t guarantee that the … Read more
Another option is the built in Patterns starting with API Level 8: public final static boolean isValidEmail(CharSequence target) { if (TextUtils.isEmpty(target)) { return false; } else { return android.util.Patterns.EMAIL_ADDRESS.matcher(target).matches(); } } Patterns viewable source OR One line solution from @AdamvandenHoven: public final static boolean isValidEmail(CharSequence target) { return !TextUtils.isEmpty(target) && android.util.Patterns.EMAIL_ADDRESS.matcher(target).matches(); }
What about this? bool IsValidEmail(string email) { var trimmedEmail = email.Trim(); if (trimmedEmail.EndsWith(“.”)) { return false; // suggested by @TK-421 } try { var addr = new System.Net.Mail.MailAddress(email); return addr.Address == trimmedEmail; } catch { return false; } } Per Stuart’s comment, this compares the final address with the original string instead of always returning … Read more
See RFC 5322: Internet Message Format and, to a lesser extent, RFC 5321: Simple Mail Transfer Protocol. RFC 822 also covers email addresses, but it deals mostly with its structure: addr-spec = local-part “@” domain ; global address local-part = word *(“.” word) ; uninterpreted ; case-preserved domain = sub-domain *(“.” sub-domain) sub-domain = domain-ref … Read more