1. Setup an IMAP email account on your iPhone
2. Setup a POP email account on your iPhone
3. Setup a Gmail account on your iPhone
4. Setup a Yahoo! email account on your iPhone
5. Configuring your email settings on your iPhone
6. Setting up your email signature on your iPhone
7. Change your email password on your iPhone
8. Delete an email account on your iPhone
Check instructions for your specific iPhone model for more details.