To access your mail client, unless using a custom mail setup, you should find the following settings to be adequate.
You will need to ensure that you have the relevant DNS records configured for this to work.
Protocol: IMAP
Username/Email: user@example.com
Password: Your password
Incoming mail server: mail.example.com
Port 143
Outgoing mail server: mail.example.com
Port: 25
Protocol: POP/POP3
Username/Email: user@example.com
Password: Your password
Incoming mail server: mail.example.com
Port 110
Outgoing mail server: mail.example.com
Port: 25
N.B: With a POP connection, you may want to consider enabling the option to delete mail from the server when it is deleted from the client.
Please ensure that you have SMTP authentication turned on in both instances.