April, 2005 CCS News: Trouble Sending Email When Offsite?

April, 2005

Trouble Sending Email When Offsite?

If you are offsite and unable to send email using the Lab’s offsite outgoing mail server, you may have been blocked by a local Internet Service Provider (ISP). ISPs block connections to outgoing mail servers that are not owned by the ISP. An increasing number of ISPs (like SBC, Earthlink, Comcast) are doing this to help stop viruses from sending email out once they've infected a computer on the ISP's network. As a result, users of the ISP's network are required to use the ISP's outgoing mail server to send email.

Though the ISP blocks the sending of mail, users are able to read your email on imap4.lbl.gov because access to that server happens via a different type of connection (the IMAP protocol, as opposed to the SMTP protocol used for sending). Worms do not cause problems using the IMAP protocol, so it's not typically blocked by ISPs.

ITSD is looking for some long-term solutions for this. Until then, here are some options you can consider today:

Use Webmail. Webmail is simple and free. There are some disadvantages, however, such as no access to personal email address books.
Use VPN (Virtual Private Network). VPN creates an encrypted, virtual extension of the Lab's network, and circumvents ISPs' blocking. VPN is not guaranteed to work in all situations (e.g. some ISPs block encrypted traffic or VPN connections explicitly). VPN is $12/month.
Use the ISP’s outgoing mail server. If it's possible to find out the ISP's outgoing mail server, you can tell your email client to use that server while on that ISP's network. This is generally what ISPs prefer, though it can be tedious if you frequently use different networks on which the ISPs are blocking external SMTP connections.

For details go here.

If you have questions, contact the Help Desk at x4357.