but will send me money via cashier's check or money order right away via a relative!!! One even asked for my banking info to "wire" me the money
All of them are scammers. If they send a check it will be for more than the rent. They will ask you to send some of it to someone for some reason. The check will be fake. If you give them your bank information they will wipe out your account. The best thing to do is not reply to anymore of their emails and delete the emails you have.
You could post the emails you have so if anyone does a google search they will find it posted. Another thing you should do is to check the IP address. This will tell you where they are really located. To do this you will need to open the full headers. Then copy and paste them in the box at the link below. Then click on submit header for analysis.http://www.iptrackeronline.com/header.php
If you are using yahoo go to the bottom of the email and click on full headers. If you are using gmail click on the down arrow next to reply then click on show original. Sorry but these are the only two email providers that I know how to find the full headers.
IP Addresses all originate from California
Califrona is where yahoo is located