How to Unblock Your E-Mail
Aug 23, 2005 7:00 AM PT
Ah, e-mail, the lifeblood for millions of businesses across the globe. What would we do without it?
In last week's article, I discussed What to Do If Your E-Mail Is Blocked. Just as there are precautions that you can take to retain access to e-mail privileges, there are methods which you can use to regain e-mail access.
Where to Begin
What can you do if your e-mails are not being received? If this happens to you, then one or more blocks have probably been instituted by the recipient's e-mail service provider:
- Your individual e-mail address is being blocked,
- Your e-mail server's IP address is being blocked, or
- The IP address used by your computer to communicate with your e-mail server is being blocked.
If your individual e-mail address is blocked, then your options are limited to obtaining another address and then not sending unwanted e-mails from that new address. Learn e-mail traps to avoid in business so that people do not label your e-mail as spam.
If the Internet protocol (IP) address that your firm uses is blocked, this indicates larger organizational problems.
Some ISPs in the U.S. block all e-mail from IP addresses known to be responsible for spam or other forms of Internet abuse. (An IP address is a series of four sets of numbers, with a maximum of three digits per set, and with each set of numbers separated by a dot, e.g. 18.104.22.168.)
Although the Internet service providers (ISPs) of your e-mail recipients can be asked to unblock individual IP addresses, this may not provide much benefit if an IP address continues to be responsible for spam, virus attacks and other abuses that will result in new blocks being imposed. A better option is to have your organization and its ISP take practical steps to keep any of its IP addresses from being included on lists that other ISPs use to determine which addresses to block.
If your ISP is not protecting the IP address that you use, you need to consider shifting your business to an ISP that actively protects its IP addresses.
How to Protect Your IP Address
Prohibit open relays: Open relays allow e-mail to be received and sent to any source. Closed systems only allow e-mails from password-protected customer accounts to be sent out. Your personal computer can be turned into an open relay if it is not properly protected by a firewall and antivirus program, or someone -- intentionally or unintentionally -- downloads a trojan program that is used to take control over that machine.
According to the Spamhaus Project, "Over 70 percent of current spam comes from proxies (PCs infected with viruses/trojans). Since the release of Sobig, the first commercial spam virus designed by spammers to infect PCs [by] turning them into networks of proxies through which spammers then send millions of spams anonymously, spammers have released countless virus variants, mostly variations of the original Sobig code, and have been infecting an estimated 80,000-100,000 new PCs every week."
Limit outbound traffic: Yahoo's e-mail service sets a limit on the number of e-mails that can be sent out every 15 minutes. Other e-mail providers limit the number of addresses to which an e-mail can be sent. Richard Stockton, webmaster at Adhost, said that he receives requests from customers to temporarily lift limits on the number of recipients so that newsletters can be sent out through Adhost's e-mail server.
Stockton said that at Adhost they always refuse requests to temporarily increase the number of e-mail recipients allowed from their current cap of 99. Instead, they refer requestors to WhatCounts.com, a 3rd-party company that handles bulk e-mail and newsletters.
Respond to complaints: Complaints provide warnings to ISPs that some of their users may be putting that IP address at risk of being placed on a list to be blocked, but responding to complaints can cost an ISP valuable staff time, and so many of them do not spend the resources to maintain an active complaint response system. However, some managers of lists of blocked IP addresses monitor to see if an active complaint system is in place. If they are not satisfied with the complaint response program for an IP address or group of IP addresses, these managers will include the addresses on their lists for blocking.
If you want to protect your e-mail service from interruption, select an ISP that goes out of its way to respond properly to complaints. Responses to cases of abuse can begin with warnings, and then lead to termination of service or, in extreme cases, to referrals to law enforcement agencies.
Monitor outbound traffic: Adhost uses MRTG (multi-router traffic grapher) to monitor outbound traffic and detect unusual activity which could indicate outbound spamming or a breached computer inside Adhost's network. Observer from Network Instruments is a packet analyzer that runs on top of MRTG.
WinPcap and Ethereal are freeware packet capture and analysis tools. Windows drivers do not support Ethereal's ability to capture traffic on WiFi networks, but Ethereal still functions well in other network environments.
How to File Complaints
To file a complaint, display the full text of an offending e-mail, including full header information, and look for the originating IP addresses. If your ISP has quarantined the virus, they will normally send a notification to you that includes the originating IP address.
The ISP responsible for the IP address can be identified by conducting a whois search. North American IP address searches can be conducted on the American Registry for Internet Numbers, also known as Arin.net. Asian addresses are maintained by the Asia Pacific Network Information Center, also known as Apnic.net. If the offending address is not found on one of those directories, the directory will usually refer you to the correct directory.
The online directories will list the contact information for the complaint desk at the ISP that is responsible for an IP address or block of addresses. A complaint may be sent to that contact, with a copy sent to your ISP, neither of which is obligated to respond to you (hence the blocking process). If you need to keep receiving e-mail from the offending IP address, then you may wish to keep your ISP out of the complaint loop.
The originating e-mail address may not have anything to do with the origin of a piece of spam. E-mail addresses of innocent people are harvested by spammers and used to send out spam. That is why going after the IP address is often the best strategy for stopping spam.
Next week, we will take a closer look at the problem of spam and describe the leading sources of spam.
Anthony Mitchell , an E-Commerce Times columnist, has been involved with the Indian IT industry since 1987, specializing through InternationalStaff.net in offshore process migration, call center program management, turnkey software development and help desk management.