Get email address from mailbox string

You can use imap_rfc822_parse_adrlist to parse that address:

$addresses = imap_rfc822_parse_adrlist('My name <[email protected]>');

at face value, the following will work:

preg_match('~<([^>]+)>~',$string,$match);

but i have a sneaking suspicion you need something better than that. There are a ton of "official" email regex patterns out there, and you should be a bit more specific about the context and rules of the match.