Email Systems
Mail Server Settings of IIS
POP3/IMAP server: mail.iis.sinica.edu.tw
POP3, IMAP, POP3s, IMAPs mail services are available in IIS networks. Only POP3s and IMAPs are avaiable outside of IIS networks.
Outgoing(SMTP) server: mail.iis.sinica.edu.tw
SMTP and SMTPs are available in IIS networks. Only SMTPs is avaiable outside of IIS networks.
1. Domain Name
iis->Institute of Information Science
edu->educational institute
tw->Taiwan

If the receiver is in the same domain as yours, the domain can be omitted.
On the other hand, if you send to John in UIUC, the address cannot be abbreviated and needs to be john@uxa.cso.uiuc.edu

2. IP
Another type of format uses IP address, such as username@$ip_address$. For example if you send to hsu in the computer center, the address can be hsu@$140.109.14.2$.
Auto-Forwarding

Auto-forwarding helps you forward the mails in your iis mailbox to your other accounts. This can be set in the auto-forwarding function on webmail.