Why SSL with IMAP and SMTP
It Protects Sensitive Information
Part of the process of checking your email via IMAP requires you to log in with your departmental account username and password. Plain IMAP will transmit your password over the network in clear text. It is possible for your password to be intercepted by an unethical party snooping the network traffic. When SSL is used, this connection is encrypted and significantly more secure.
It Bypasses Your ISP's Mail Server
We also require the use of SMTP with SSL for any machine outside Olsson Hall, as it is becoming commonplace for ISPs to use an intercept proxy for services like SMTP. This is an anti-spam measure which allows the ISP to impose restrictions on mail sent on their network. Their proxy will intercept any mail sent to port 25 and redirect it through the ISP's own mail server. This can cause our users various problems with sending email. By enabling SSL (which runs on a non-standard port number), you can bypass the proxy and send your email directly to mail.cs.virginia.edu.