Outlook 2007 550 5.7.1 error in Gmail only

Outlook using Gmail POP working fine at 11 last night. This morning problems with Gmail POP and IMAP. All other POP accounts are fine. I have another machine with a Gmail IMAP setup that is producing the same error. I've tried the Internet but can't find this exact error. The syntax of the message does not make sense: The following recipient(s) cannot be reached (name obscured by Xs): 'XXXXXX XXXXX' on 8/6/2014 8:23 AM 550 5.7.1 the custom from if you believe this to be in error. ot3sm1983214obc.13 - gsmtp Help would be greatly appreciated.