I thought this as well, until looking for info one day and stumbling onto this: http://stackoverflow.com/questions/386294/what-is-the-maximum-length-of-a-valid

I thought this as well, until looking for info one day and stumbling onto this: http://stackoverflow.com/questions/386294/what-is-the-maximum-length-of-a-valid-email-address http://stackoverflow.com/questions/386294/what-is-the-maximu... Turns out the 320 value was actually incorrect, its 256 but the mailbox is wrapped in square brackets, so 256 - 2 = 254.