Our official policy on RBL/blacklists – ExchangeDefender Blog

May 28, 2008

Our official policy on RBL/blacklists

Filed under: ExchangeDefender,Offsite Backups — vlad @ 10:52 am

With more and more misconfigured mail servers generating junk rejections we felt it was time to discuss our official policy on realtime blacklists (RBL) and the extent to which we support them.

First of all, all Own Web Now Corp mail servers and every piece of mail leaving our network is scanned for SPAM, Viruses, malware and just about everything we scan inbound mail for we also scan outbound mail for. We do not allow open/blind relaying, we disinfect anything dangerous and take every precaution to keep dangerous content off the Internet. However, from time to time something may slip. Clients still get infected with viruses, clients still use weak passwords or their systems that open up their infrastructure to worms and mail blasts, stuff happens.

OWN Network Operations monitors network activity and RBL lookups 24/7/365 and if there is an item that slipped our post and made it into an RBL (it usually takes just one piece) we immediately quarantine the user and request removal. We monitor over 100 RBLs and immediately act to make sure none of your mail is returned or bounced.

However, as more and more mail server administrators lose control over their servers, they start implementing policies that affect the ability to deliver legitimate mail to them. Because some of the best RBLs are also commercial some users stoop to stealing DNS RBL zones, longer RBL lookup caching to avoid being rate-limited and kicked off the free service, or their mail servers simply have no resources to fight with the SPAM.

Because our servers act as a transparent stateful proxies, meaning that we deliver your mail on your behalf, if there is a time that we have to return the message you will see outbound.exchangedefender.com as the server providing information on why the message was returned. This does not mean that outbound.exchangedefender.com rejected your message, it is simply quoting the error it received from the remote server.

Own Web Now Corp does not have control of the remote servers, it usually does not have a relationship or contact information for neither the sending server (you) or the recipient (where you are sending mail) so we are unable to help with any rejections that happen outside of the generally accepted rules and protocols around mail delivery. If the mail server on the other side didn’t implement their RBL directives correctly, if they are overloaded, if they manually chose to program in a configuration to reject your mail or anything out of the normal course of server management – we can’t help.

If you are seeing sources that are not adhering to these generally accepted rules such as quoting why the IP was blocked or message returned, we recommend you remove outbound.exchangedefender.com from your smarthost configuration and route messages to them directly. If that fails as well, try to contact the mail server administrator if you can locate their contact information. If you are tech savvy, you can create an SMTP connector for a given address space and route mail for particular domains directly to their mail servers, bypassing ExchangeDefender outbound proxies completely.

Just to repeat, we constantly monitor network traffic and actively keep our servers off RBLs that you can find at www.dnsstuff.com. We do everything in our power to assure mail delivery but if the configuration change on the remote end specifically interferes with that delivery that is the place you need to contact and find a way to get mail from your network delivered to theirs.