[desas]

Gmail works with . as delimiter as well as +

[blop]

with gmail you can do:

    foo+anything  => redirected to foo
    foo.something => redirected to foosomething (so . is not the same as +)

The + isn't always accepted in dumb email checks though, and spammers know about it...

[MaKey]

I believe you can insert dots as you wish but not use it like the plus sign. So [e-mail] is the same as [e-mail] but [e-mail] is another account than [e-mail].