Tellurian Networks (TN) utilizes many technologies and lists to maintain mail server operations and to minimize the spread of viruses, worms, and unsolicited bulk email (aka: spam). In the interest of full disclosure and to let our customers know what TN does with all mail services which may affect a customers' ability to receive or send email or to reach certain web sites, TN has published this complete listing with all email policies detailed.

Tellurian Networks operates four main mail servers. A bastion host which performs anti-virus and anti-spam filtering (vegan.tellurian.net/spamfilter.tellurian.net) for corporate vmail accounts, a corporate accounts backup SMTP gateway/bastion host (smtp-forward.tellurian.net), the virtual domain mail server (vmail2.tellurian.net) where all virtual mail server accounts (user@yourdomain.com) user email is received and stored and the main mail server (mail.tellurian.net) where all tellurian.net/tellurian.com/garden.net user email is received and stored. vmail1.tellurian.net is a legacy server which is being decommissioned, therefore, this page is not accurate for accounts on that server. Due to the complexity of rules needed for backup mail relay, which would significantly reduce spam filtering ability, Tellurian does not utilize backup MX records and multiple mail servers for relay. However, Tellurian does cluster mail servers for maximum uptime and reliability.

Filtering policy for vegan.tellurian.net, vmail2.tellurian.net, and mail.tellurian.net

All three of these servers run the same software. The policies set on both of these servers affect all @tellurian.net, @tellurian.com, and @garden.net email addresses and all corporate virtual-mail (vmail) customers who pay for our anti-virus and anti-spam filtering services.

These servers use the AVAST engine to detect and refuse virus infected messages. All infected files detected will be deleted and refused upon receipt. Password protected zip files will also be rejected. Due to new viruses and worms which are constantly written and modified, not all viruses and/or worms will be detected. Keep your computer's anti-virus program(s) up to date and do not open ANY unknown and/or unexpected file attachments. No anti-virus program or service can protect you against every threat so you must use common sense and good judgement!

To help protect customers from contracting or spreading viruses and/or worms, this server blocks the sending and receiving of executable email attachments with the exception of .exe and .com files which should be renamed to _exe and _com. This may not always happen though due to MIME encoding errors and variations.

Individual user control of spam is extremely important to Tellurian. We believe in empowering our clients to make their own choices regarding what they receive and what they block. Every user who has paid for spam filtering has the ability to login to their account to setup global exceptions, whitelist addresses, and spam hold and delete numerical thresholds.

These servers use rules-based filtering which use a multitude of tests to determine if a message is spam based on a numeric score for each test. The filtering process uses two files: an automatically updated ruleset which is updated based on global spam trends for all users of surgemail (our mail server software) and a locally maintained rule file which modifies the standard behavior slightly and adds our own anti-spam rules to make the filtering even more accurate.

This server uses CRC technology to identify spam. A checksum is generated for each email message received which is checked against a database of known spam which is updated every 60 minutes. If the message matches spam submitted by two other servers, we will tag the message as spam. Many users also report their messages which are added to the database as spam samples

Sender Policy Framework, or SPF is a technology used to detect email forgery of domains on the Internet. An owner of a domain may publish information in DNS stating where email is supposed to, or allowed to originate from for their domain name. If email comes from a source than what an SPF record specifies and delivery is attempted to one of our servers, the default action will be to reject the message. Every user has the ability to make exceptions on a case by case basis should this cause a problem. Users can also disable listening to SPF entirely for their own account if so desired. Should you disable the use of SPF on your account, SPF will still be used in scoring messages that arrive. We highly recommend you leave this setting enabled as it stops a great deal of spam, forged email, scams, and misdirected bounces should you use autoreplies. The only time this might cause a problem is if incorrect information is published in the SPF record, or an end user hasn't been informed of the sending policy of a domain at which they have an email address. More information about SPF can be found at http://spf.pobox.com. Tellurian Networks publishes SPF records for tellurian.com and other domains for which we host the email to help prevent abuse of these domains.

This server utilizes many server "blacklists" to protect TN server resources from being used by senders of unsolicited bulk email (aka: spam). Some of these lists are IP (Internet Protocol) based which means that TN's servers do not examine to/from addresses or any other content when filtering based on these blacklists. The decision is based solely on the originating server's IP address. Other lists use the domain name in the from and/or received headers. One of these lists is the RFC Ignorant list. We add points for sites which do not accept email for abuse@domain.com and postmaster@domain.com which is a violation of RFCs.

All lists currently in use will only affect a users ability to RECEIVE mail ONLY IF the user has enabled filtering, but WILL NOT restrict our users ability to send mail to any address, server, or domain.

• The ORDB.org blacklist is a database of machines by IP address which are reported and then tested and found to be open SMTP (Simple Mail Transfer Protocol) relays — SMTP relays are, or can likely be, used as conduits for sending unsolicited bulk email. Open relays are often used by spammers more than for legitimate email once they are discovered and shared with other spammers. A match for this list adds 1.5 points to the spam score.

• The SpamCop blacklist is a database of known and/or reported spammers by server IP address. We selectively return email sent by servers in the spamcop database. This list has a high false positive rate, so we don't pay too much attention to it alone, but it helps bump the score up a little. A match for this list adds 1.25 points to the spam score.

• The DNSRBL blacklist is a list of IP addresses of machines known to be either direct SPAM sources or Dial-up (dynamic address) pools which would never be a source of non-SPAM eMail. These machines really should never send mail to our server directly so if they are, it is probably spam. A match for this list adds 2.0 points to the spam score.

• The Spamhaus blacklist tracks the Internet's worst Spammers, known Spam Gangs and Spam Support Services, and works with ISPs and Law Enforcement Agencies to identify and remove persistent spammers from the Internet. A match for this list adds 3.5 points to the spam score.

• The NJABL is Not Just Another Bogus List. This effort began out of frustration with the amount of spam coming into their networks and with the lack of options for an existing dnsbl with policies and stability we could live with. NJABL.ORG maintains a list of known and potential spam sources (open relays, open proxies, open form to mail HTTP gateways, dynamic IP pools, and direct spammers) for the purpose of being able to tag or refuse email and prevent at least some spam. A match for this list adds 1.5 points to the spam score.

• The Distributed Server Boycott List contains the IP addresses of servers which have relayed special test messages to listme@listme.dsbl.org; this can happen if the server is an open relay, an open proxy or has another vulnerability that allows anybody to deliver email to anywhere, through that server. Note that DSBL itself doesn't do any tests; it simply listens for incoming test messages and lists the server that delivers the message to DSBL's mail server. TN uses both list.dsbl.org and unconfirmed.dsbl.org to block spam. A match for this list adds 1.0 point to the spam score.

• The http://countries.nerd.dk hosts a database of all assigned IP addresses and in which countries they exist. Since a large percentage of spam travels through China due to huge numbers of misconfigured servers which are open proxies and open relays (presumably in part to the language barrier which makes it difficult for Chinese administrators read the FAQs on securing their servers.) TN uses cn.countries.nerd.dk to identify messages from Chinese servers. A match for this list adds 1.25 point to the spam score.

Whether or not a given message is rejected is based on the individual user settings specified here for tellurian.com/net & garden.net addresses: http://spamfilter.tellurian.net/cgi/user.cgi and here for corporate customers: http://spamfilter.tellurian.net/cgi/user.cgi and the total point value assigned by adding all the rules above.

These servers utilize "spam traps" to quickly tag and identify spam in near real-time. As such, the email address of spmtrp@tellurian.com has been established to be harvested by potential "spam bots" and email sent to that address will be recorded as spam. PLEASE DO NOT SEND E-MAIL TO THIS ADDRESS UNDER ANY CIRCUMSTANCE.

All email messages in users' Trash folders on our mail servers are erased nightly to conserve disk space and optimize server performance. This is not a user configurable option. Trash is exactly what the folder says and all messages will be deleted. If you wish to save old messages, make folder(s) for messages you wish to keep and transfer messages to these folders.

All email accounts which are not checked at least once every 6 months will be emptied of all contents. Check your mailbox at least twice per year to prevent this grooming process on your mailbox.

Upon account deactivation or deletion, ALL email messages and address book entries on TN servers will be deleted immediately.

Filtering policy for smtp-forward.tellurian.net

smtp-forward.tellurian.net performs only anti-virus filtering at this time. This server uses the AVAST engine to detect and refuse virus infected messages. All infected files detected will be deleted and refused upon receipt. Password protected zip files will also be rejected. Due to new viruses and worms which are constantly written and modified, not all viruses and/or worms will be detected. Keep your computer's anti-virus program(s) up to date and do not open ANY unknown and/or unexpected file attachments. No anti-virus program or service can protect you against every threat so you must use common sense and good judgement!

Filtering policy for vmail1.tellurian.net

vmail1.tellurian.net performs no filtering at this time nor do we anticipate adding it in the future. This machine simply sends and/or stores what it receives.

Additional Information

Here are a few useful links to learn more about the origins of spam and what can be done to stop or minimize it:

• Junkbusters - Essential tips, tools and news here help you combat both email and junk snail-mail.

• Brightmail - This service filters spam out of your POP3 email account, and it's free to individual users.

• Spamhaus - A rogues' gallery of known spammers and the ISPs that keep them in business.

• SpamCop Help spam merchants get what's coming to them—use SpamCop to tell their ISP what's going on.

• The alt.spam FAQ - Everything you ever wanted to know—and then some—about the odoriferous business of bulk email.

• Cloudmark SpamNet Plugin - For Windows 98/NT/2000/XP and Outlook 2000/XP.