Seven Tips for Securing Your Organization’s Network from Spam and Email Viruses

Providing safety towards e mail similar threats has grow to be a burden for many IT pros in 2006. According to a contemporary find out about by way of Postini, junk mail and e mail viruses now make as much as 80% of all emails despatched out as in comparison to 50% in 2000. As a consequence, IT pros now face a more difficult problem in offering community safety for this quantity of junk mail. IT pros even have the drawback of protecting towards new types of e mail threats similar to junk mail zombies, listing harvest assaults, mass mailing trojans, in addition to the most recent e mail virus.

In this newsletter, I’ve indexed the seven most efficient junk mail combating pointers for organizations with in-house mail servers. These seven pointers are confirmed ways I’ve used for my consumers, companions and co-workers who need to tighten their perimeter (community) safety.

1. Firewall:

A firewall is your first defensive position towards hackers, crackers, and spammers. Without a firewall, your community is a crisis ready to occur and may give any newbie hacker loose reign over your community. If your company has a couple of Internet customers, this instrument is very important for securing your community.

2. Block Port 25:

On your firewall, permit outbound visitors on TCP port 25 for all mail servers. Block visitors on outbound TCP port 25 for all different computer systems and servers. On the Internet, TCP port 25 is used for e mail visitors via SMTP (Simple Mail Transport Protocol). Blocking this port is a great safety apply and forestalls mass mailing worms and junk mail zombies from sending mail out of your customers’ computer systems.

3. Managed Email Filtering:

Consider the use of a controlled filtering resolution similar to Postini, Brightmail, or SpamCleaning soap. Managed Email Filtering services and products quarantine junk mail, viruses, and e mail threats prior to attaining the e-mail servers to your community. In comparability to desktop filters and server home equipment, controlled filtering services and products supply awesome perimeter (community) coverage by way of fighting supply of junk mail and viruses in your community and servers.

4. Check Relay Setting:

A mail server’s relay environment controls which computer systems and servers are ready to ship SMTP e mail to your group’s behalf. Check your settings and restrict the IP cope with vary to e mail customers to your native community. Some mail servers have settings to restrict e mail relay via authentication. If authentication-based relay is to be had, setup and configure it too. NOTE: If the relay isn’t set correctly, spammers will be capable of ship e mail out of your mail server. This exploit is usually referred to as an “Open Relay” or a “Spam Relay.” Use the Open Relay take a look at at [] to test if spammers can relay mail out of your server.

5. Black Lists:

Setup your mail server(s) with a black listing. A black listing (black hollow listing) is a database or checklist of identified junk mail resources. Most trendy e mail servers may also be configured to question inbound e mail towards on-line blacklists. Messages originating from those resources can then be blocked. I like to recommend configuring your e mail server with SpamHaus blacklist. is a superb loose provider to make use of. Some different just right blacklists are DBSL and SpamCop.

6. Reverse DNS:

Reverse DNS (rDNS) pals an IP Address with a Domain Name. Most mail servers, as an anti-spam characteristic, incessantly use a opposite DNS look up to check an e mail cope with area identify with its IP cope with. If the IP cope with discovered from the rDNS look up does no longer fit the area identify, it’s most definitely junk mail. If you haven’t carried out so, setup and configure opposite DNS data to your DNS server.

7. Anti-Virus Scan:

There are many gear that supply good enough anti-virus coverage for desktops on the place of business. Most anti-virus device is just right at detecting viral threats that proliferate e mail junk mail similar to mass mailing worms, trojans, and listing harvesters. Large organizations may wish to use endeavor anti-spam device with control and tracking gear that may permit monitoring of community virus outbreaks.

Recommended Links: [Postini service – managed filtering, 1 to 500 users] [Postini service – managed filtering, 500+ users]

– [] [Blacklist] [Blacklist] [Blacklist]

– [] [Open relay test] [DNS report/open relay test] [Spam database lookup and open relay test]

– [] [Spam Zombie Article]

Email viruses and similar threats delivered via junk mail have price companies billions of bucks in bills and misplaced productiveness. Each junk mail e mail despatched or won out of your area prices your company cash and bandwidth. By imposing those seven pointers, your company can cut back junk mail and get well prices.

This article: &replica; Copyright 2006 Todd Green and loose for republishing.