This means you don’t have to use 163.com’s webmail interface! You can check your email and send messages using other email programs (like Mailspring, Outlook Express, Apple Mail, or Mozilla Thunderbird). Using desktop email applications can improve your workflow. They typically offer more options, and your email is still available on your computer when you’re disconnected from the internet.

Incoming Settings

The IMAP server is imap.163.com and it is using the port 993. It requires SSL. 

The POP server is pop.16.com and it is using the port 995. It requires SSL. You can also use port 110 

Outgoing Settings

The outgoing SMTP server is smtp.163.com, and it is using the ports 465 which requires SSL, and 587 that requires TLS.

Your email address is your username.

source: 163.com