If you know you email adresses don't include < (which is _very_ dangerous if you allow things like Mr Bean >bean@dumb.uk>) then you can just get the addresses with:

which just gets stuff with an at sign in a td

Otherwise grab your copy of Mastering Regular Expressions (buy it if you don't have it, it's your Friend) and look for the explanations on "unrolling the loop"

Update: hey, I'm dumb or wot? If it's HTML shouldn't the < be escaped into &lt; anyway? In this case the regexp above would work in any case!