That's not a valid URL because of the @ in the username - you're trying to give it a port of "Meh@gmail.google.com". You likely need to URL encode the @ in the username, though that may not work (and the URL format for that may not be possible).
Well, I was wrong with my last statement (I can only blame myself, and probably my Sun thin client). Encoding the @ does pass the regex filter. However, XenForo gives me a 401 when I preview the feed. When using Chrome or FF with the @ 'encrypted' (%40), same thing occurs and I have to use the @ sign. Is there no way around this besides manually editing the DB and hoping for the best?