Could be days, could be weeks. That email you got on the 18th was the "don't bug us" email. For the past few months people have been reporting getting rifles within 2-3 weeks, but apparently they're pretty busy with the 6 million SN garands, the kimber 82g's, the rimfire ammo, upcoming matches prompting more buyers, general election time paranoia prompting more buyers, Obama's gun ban comment prompting panic buyers, CA's pending long gun registration in 2014 screwing with CMP purchases, etc. etc.
Nothing to do but be patient and wait.