In order to update email setting in your Mac Mail 10 or Mac Mail 9 users must keep following points on mind these are:
• Under incoming mail server, enter your correct username
• Under Outgoing mail server option, choose to edit the SMTP server list
• Now you need to enter username, password and hostname in the field provided
• Use the correct port number for both incoming and outgoing server
This can be really tricky at a time if you don’t know the correct hostname and port number that’s why it is advised to call professionals at AOL mail signin support for fixing this issue completely from the core itself.