How to use Bitmap Checking in Antispam Admin
Question asked by Scott Hendrickson - 12/17/2015 at 12:16 PM
Hi Everyone! 
In Antispam Admin for RBLs, there's a checkbox to Enable Bitmap Checking, but there's no good explanation on how to implement it.  In SM's help it says only that you can use this feature if the RBL supports it.  I understand the concept of bitmapping (actually bitmasking I think): List A returns 2; list B returns 4; list C returns 8; if the subject is on A and C, the return is 10.  However that doesn't tell me what to enter into SM's Required Lookup Value(s) box.  Am I supposed to enter the sum of the returns of the lists I want to check?  I know I could also just enter the individual returns separated by commas.  I just thought bitmap checking would be more efficient. 
I look forward to hearing your comments. 
Thank you! 
Scott Hendrickson
SOS4Net, Inc.
Centennial, CO. U.S.A.

3 Replies

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Scott Hendrickson Replied
Could someone from SmarterMail please respond to this post?  I can find nothing in the documentation that explains how to use Bitmap Checking when configuring an RBL or URIBL.  I even checked with Bruce Barnes, one of the most knowledgeable SmarterMail admins out there: Even he didn't have any more info than what's in the docs, which says only that you can use Bitmap Checking if the list supports it.  It says nothing about what SmarterMail does with it.
Scott Hendrickson
SOS4Net, Inc.
Centennial, CO. U.S.A.
Bruce Barnes Replied
Thanks for bringing this up on the forums, Scott!

Regarding Scott's comments . . .   I've been researching the bitmap checking capabilities of both the RBLs included in my antispam document as well as those not included, and have found nothing, on any of the RBL database websites, to indicate whether or not they support bitmap checking.
In the e-mail traffic that has taken place between Scott and myself, he brought up the fact that my current document (as of 31 Dec, 2015), included at least one RBL which had bitmap checking enabled and wanted to know what my experience was with how a rough bitmap might be handled.
My response was, and still is:  I have no idea.  I've seen nothing and have nothing to report on whether or not this is actually checked by any RBL database providers.
So, group(s):  anyone else have anything to contribute with regard to RBL bitmap checking?
Bruce Barnes
ChicagoNetTech Inc

Phonr: (773) 491-9019
Phone: (224) 444-0169

E-Mail and DNS Security Specialist
Network Security Specialist

Customer Service Portal: https://portal.chicagonettech.com
Website: https://www.ChicagoNetTech.com
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Web and E-Mail Hosting, E-Mail Security and Consulting
I was looking for an explanation of what "bitmap checking" in SmarterMail antispam does and how it works, and I came across this post with no answers ...

Now I ask SmarterTools if it is possible to have a guide explaining how to use this function.
Gabriele Maoret - SERSIS - Head of SysAdmins
Currently manages 3 SmarterMail installations (1 in cloud for SERSIS which provides service to a few hundreds 3rd party Mail Domains + 2 on premise to customers)

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