How to prevent the server getting blacklisted and to get removed from a blacklist database.
Spam is a huge problem on the Internet and as a mail server operator it is important to take reasonable steps to ensure that the server is secured from being hijacked by those wishing to distribute bulk unsolicited e-mail.
If the server is not configured correctly, spammers
can use the mail server to dispatch messages through the server
uninhibited. Mail servers accept messages for recipients that have their
mailboxes hosted on the mail server itself, but it is critical to regulate who
can send messages to others (non-local recipients). Secure the server by
configuring strict rules as to who can use the server to send messages
(relay messages) to non-local recipients.
The article Article ME020001describes which relay settings are most appropriate.
It is possible to get blacklisted or have your server IP(s) blacklisted via notifications being incorrectly sent to a forged senders address. Here are the common ways that notifications or bounced messages where replies to a forged address from a message envelope can have you added to a blacklist;
Another way that your server could be blacklisted is through blacklisting of a range by a DNSBL. Here is a returned warning from the web site of a DNSBL after a server range has been blacklisted;
WARNING!!!! This entire Class C, /24 network is listed!!!
2 or more /32 server entries in any /24 network will get the entire /24 network listed on ricn.dnsbl.net.au and rmst.dnsbl.net.au
If the server is not secured from unauthorized relay, it will end up on an Open Relay Blacklist. Once the server is on a black list, the removal process is very time consuming. The removal process is as follows:
1. First ensure that your server is no longer open
relay. Make sure that the server is configured as suggested in the article Article ME020001
2. Next, determine which open relay black lists the server is listed on using the tools at www.dnsstuff.com.
3. Finally, go to the web sites of each Blacklist provider and use their web site to submit your site for testing.
4. Blacklist providers usually process removal requests within 24 hours. They will send a mail message to indicate the status of the removal.
How to configure DNS blacklisting: Article ME020162Blacklisting mechanisms:: Article ME020084
|Product:||MailEnable (All Versions)|
|Keywords:||blacklisted Blocked IP Reject blacklist removal black list blacklisted open|
|Class:||HOWTO: Product Instructions|
|Created:||1/07/2003 6:04:00 PM|
|Revised:||Wednesday, May 4, 2016|