Hi folks, I would add to the issue the portion of the message that says "from some people". When we got that yesterday creating Josh's account (Josh in CC), we found it a bit weird (why from me? what is wrong about me?).
So I suggest your clearly state that the anti-spam has blocked the account creation, so it clearly shows it is not personal, just computer rules (spammy heuristics as described by pabs on IRC). Thanks for taking care of it! Happy hacking, Tassia.