To host your email with another provider, you need to do the following:
1. Login to your control panel and go to the DNS Zone Editor.
2. Delete the A Record called MAIL and delete the MX Record called mail.domain, do the same for MAIL2. A & MX Record.
3. Create new DNS Records, do not allow them to begin MAIL ie MAIL0 MAIL02 etc. example call your record EMAIL or MyMail.
4. Create your MX Records.
5. Make sure all POP3, Email forwards & Mailing lists etc for that domain are deleted. If they are not deleted you will experience email problems.