I've hit enough sites that refuse to accept a + in email addresses that I gave up using it, on the basis that I couldn't remember whether or not I was using it, per site. Standard it may be, but so many sites have bad email address validation.

Hi kchr, no you're not the only one to use the plus sign. As already discussed in this feed, the + part can easily be removed by spammers.

+1

Sorry, couldn't resist. I got burned by this, I used it to sign up to a newsletter, and when I tried to unsubscribe, I kept putting in my actual email address with no results. Took me two weeks to think of checking the "to" field and realising I'd used a plus address

Normally I only read on HN, but you got me logging in, upvoting and commenting! Probably most people just don't know about the standard. (As it is probably with most standards).

Anyways, thanks for your hint.