to be clear "+" addresses aren't a Gmail thing. they work on all mail servers. they're part of the spec for how you define an email address. Any server that doesn't support them is, by definition, broken.
Wrong AFAIK. Unless certain mail providers have been patched recently without me noticing.
> they're part of the spec for how you define an email address. Any server that doesn't support them is, by definition, broken.
Might very well be true, I haven't checked. In that case I guess a number of people get their mail from broken mail servers so they have to deal with it anyway.
http://www.faqs.org/rfcs/rfc2822.html