Added New POP Email to CRM. Only Old Emails Download. No New Emails Coming Thru

Added New POP Email to CRM. Only Old Emails Download. No New Emails Coming Thru

I added a POP email account to my CRM Email.  I have old emails being downloaded from 2013 and earlier.  But no new emails.  I've deleted over 7,000 old emails thinking that after I delete those the news ones would come thru.  Still nothing new.