That regex is defective. See benchaney's reply above.

.+@.+(\..+)?

should satisfy you both right? I use the original or a form of usually when I had to check emails.

That's identical to just doing .+@.+

Fully qualified domains actually end in a . If you're allowing sally@google then you must also allow sally@google. To be valid

No you don't. Email addresses explicitly require any periods in the domain to have at least one (non-period) character after the period. From RFC 5322, the relevant grammar production for the domain looks like

  dot-atom-text   =   1*atext *("." 1*atext)

(where atext is letters, digits, or a set of specific punctuation characters that doesn't include periods).

Ah, I wasn't aware that email addresses defined that differently. it looks like it's also the same way as part of obs-domain as defined by the addr-spec part of that. RFC 822 also seems to say the same thing, it's been way too long since i've tried to read those RFCs.

One (probably forgotten) reason people validated email addresses with convoluted regexps is that there are multiple (actually valid per RFC) email addresses formats that can do nasty things. Like explicitly specifying a series of mail servers to go through. They're (hopefully) deprecated and rejected by most servers nowadays, though.

> hopefully

Why?

> By default, this feature is turned off. This closes a nasty open relay loophole where a backup MX host can be tricked into forwarding junk mail to a primary MX host which then spams it out to the world.

http://www.postfix.org/postconf.5.html#allow_untrusted_routi...

Thankfully my email is @@@@@@@.......