I have one client that received a CP05 letter (or only one that has called me).  Yep, taxpayer and spouse each received the letter.  This is common practice with IRS to send each a letter.

This particular client has been fuming that he hasn't received his refund.  Calls me once a week to tell me how upset he is.   I keep reminding him - I do not work for the IRS.  I was glad he got the letter, it backed up what I had been telling him about the delay of his refund. Funny thing, it only made him more p!$$ed off.  His complaint about getting the letter - says if they had time to send him a letter they had time to review his return.