Mail Won't Import Messages

[JPM42]

After using the new Mail earlier today, it worked like a charm. However, I had other unrelated issues which caused me to have to start another account on my Mac and delete the one I was using, as well as its home folder. However, now, when I log on to Mail and set up the account again, nothing pops up, unless I send new mail. How can I retrieve my older mail? Thanks!