What is max number of e-mail accounts "Mail" can contain?

I experienced difficulties when establishing 8 e-mail accounts in Mail. When sending messages Mail would arbitrarily reassign the e-mail address link (from GoDaddy) belonging to, say, addy #4 to addy #8 - which of course wasn't correct, so Mail would get jammed up and I'd have to reset each e-mail address over and over again. The Genius Bar techs couldn't fix or explain the problem over several days. Apparently Mail can handle 7 accounts, as when I removed one, this nuisance stopped. Has the May 2015 Mail update changed the max number of e-mail accounts?