IP Got Blacklisted ? Try these out
magnet February 10th, 2009
Hi Magneters,
Do you know the fact that Roughly 130 billion spam emails are sent, worldwide, per day, accounting for roughly 70% of global emailing activity.
To combat this many projects were launched of which SPAMHAUS became a famous one . What the Spamhaus Team do is that they finds the source IP of spams ,from which SPAM has originated. Be it be a dynamic IP , or a static IP at user end , or a servers IP that sends or relays spam and ,adds it to the their realtime Database of IPs who are source of spams , known as The Spamhaus Block List (SBL) .
Most of the mail servers around the world check the IP details in the mails that are coming to them from outside with this IP list from SBL to ensure that they are not receiving any spams . Bingo here comes the problem!!!! . Due to the fact the most of us these days use dynamic IPs for connecting to internet . chances are more that this IP might have been already in any blacklist . and then what happens if you send a mail to a server that uses the SBL list to filter spam mails , you are caught …the server just rejects all mails from this IP .
Another interesting inference made was the fact that if you are using a Windows based Operating System without a Strong Anti virus and updated virus definitions you can be a source of SPAMs without even you knowing it. There are many known viruses that sends spam over an internet session . And the dynamic IP that you use on this internet session gets listed in SBL or other Blackisting projects lists. So the next person who will be using this IP will be the prey .
Please check this link , this was a post made by some one in 2007
http://www.manishsingh.com/archives/2007/08/mtnl_isp_blackl.html
So guess what might be the scenario now in 2009 . I doubt the ISPS here are still unaware of this . Recently when We made a call to Tata Indicom over this issue it was shocking when they told they don’t know What a blacklist is .
THE TEMPORARY CURE
But for an immediate resolution from the server end following actions can be performed. Ask the user having problem sending mails to provide us for his public IP, it can be obtained from http://ipchicken.com . and add it to
1 . vi /etc/rblwhitelist
2 /etc/skipsmtpcheckhosts
This was what we used to do but the previous week we had an issue a client was accessing mails directly from webmail . we did both these steps but the person was not able to login , instead she was getting a prompt your IP has been blacklisted . We checked further and found the interesting file , Thanks to Vishal Sir for helping us at this point , We found another important file on the server
etc/spamhaus.http.whitelist
Added her IP to this list and she could immediately login . Later we made a request to SPAMHAUS Team to whitelist the IP and they whitelisted it .
While you are sending mails from outlook e.t.c the issue can be over ridden in
another manner , turn on SMTP Authentication .
Now How Does This Helps and how done ?
SMTP Authentication is required when sending email out via most major ISP mail servers and most corporate mail servers. It is simply a username/password system which permits authenticated e-mail senders, just like most other computer accounts require authentication.
If you do not have SMTP Authentication turned on in your email software (Outlook, Entourage, Eudora, Apple Mail, etc.) you run the risk that the mail server will not recognize that you are a legitimate customer.
If the mail server is using spam filters (such as Spamhaus’ PBL or XBL) it may refuse to take your email, because it thinks you are a stranger and your dynamic IP address is probably on Spamhaus’ PBL list of dynamic IP addresses which mail servers should not accept mail from unless the sender is authorized to use that mail server.
To fix this, you need to turn on “SMTP Authentication”, here’s how:
In Microsoft Outlook & Outlook Express:
Start Outlook 2000 or Outlook Express. From the menu, select Tools, then Accounts. Click once on the appropriate account from the Mail tab. Select Properties. From the account properties dialog box, choose the Servers tab. Put a check in the box for “My server requires authentication”. Click on the “Settings” button. In the ‘Outgoing Mail Server’ dialog box, make sure “Use same settings as my incoming mail server” is selected. Press “OK”. Back at the “Properties”, click “Apply”, then “OK”. Click “OK” to close out of all dialog boxes.
In Eudora:
Open Eudora, pull down the Tools menu and select “Options…” to display the Options window. Select the “Getting Started” category on the left-hand side. Select the “Allow authentication” check box and click “OK”.
In Apple Mail:
Open Apple Mail. Click on the “Mail” menu in the top menu bar. Click on Preferences, Click on Accounts. Click on the account that you want to modify. Click on Account Information. Click on the “Server Settings…” button. In the pulldown list next to “Authentication:”, select “Password”. Enter your user name and email password (the same ones you use to retrieve your POP or IMAP email). Click on OK. Close the Preferences window by clicking on the X in the upper left hand corner of the window.
In Agent:
Tools >> Servers and Accounts >> Outbound Email Server
Connection: TLS if available
Login Method: Username and password
Advanced Settings: Port: 587
Thanks,
Alan
Systems Team