Your email program uses the POP3 protocol to download email from your email service provider’s server.
The POP3 configuration parameters for Yahoo! are:
Server: pop.mail.yahoo.com
Port: 995
Encrypted Connection: SSL
User name: Your email address
Password: Your password

Your email program uses the IMAP protocol to copy or mirror email stored on an email server to your desktop or device.

The IMAP configuration parameters for Yahoo! are:
Server: imap.mail.yahoo.com
Port: 993
Encrypted Connection: SSL
User name: Your email address
Password: Your password