[Okta Webinar] Learn how to a build a cloud-first strategyRegister Now


Filtered e-mails not listed in sender filtering

Posted on 2009-12-18
Medium Priority
Last Modified: 2012-06-27
E-mail addresses are not listed in Sender Filtering, whoever e-mails from these addresses are still blocked
Question by:Cromwellhospital
  • 3
  • 2

Expert Comment

ID: 26079297

Does the sending user get a NDR when their mail is bounced? Do you have any spam / anti-virus filtering either on your exchange server or between your exchange server and the internet.

Is your domain name cromwellhospital.com? If it is you are using message labs to filter incoming mail. Message labs has two teirs of filtering. The first is a global list that all of their filters will use to filter spam - this will include black lists and the second is a custom list you can create.

Have you tried adding the domain that keeps on getting blocked to your Messagelabs white list?

Author Comment

ID: 26079528
Getting an NDR depends on what type system the sender is using i.e. gmail systems do get an NDR while hotmail systems don't. Because there are so many senders affected I haven't checked what systems they are using, suffice to it's not gmail or hotmail, though they are the 2 systems that I Used for testing NDRs.

Spam filtering is enabled on our Exchange system but nowhere else apart from Messagelabs. There is no anti-virus filering on Exchange or between it and the internet.

Our domain is indeed cromwellhospital.com.

Evidently we do use messagelabs and subsequently their black lists and our custom lists. However these do not affect the e-mails for the following reason -

 - if I add the domain (that we're not getting e-mails from) to the senders list in exchange, wait a few minutes and then remove the domain .... e-mails from the affected domain then start coming though our system .... wierd!

Expert Comment

ID: 26084538
hmmmm - i would try telnet'ing to your exchange server and send an email from a domain that is normally undelivered. See if the email is refused at the SMTP level. If it isnt, have a look in the message tracking center and see what happens to the emails.

Agreed tho, sounds like there is something up with your senders list. Do you know if your exchange server is doing any SPF filtering?

Would be interested to see what you find when telnet'ing and in the message tracking center - I think our answer is in there somewhere.

The telnet commands would be; (I have put >> on commands you need to enter)

>> C:\telnet [mailserver] 25
220 [mailserver] Microsoft ESMTP MAIL Service ready at Fri, 18 Dec 2009 22:15:23 +0000
>> EHLO [your workstation name]
250-[mailserver] Hello []
>> MAIL FROM:test@[problem domain]
250 2.1.0 Sender OK
>> RCPT TO:administrator@cromwellhospital.com
250 2.1.5 Recipient OK
>> data
354 Start mail input; end with <CRLF>.<CRLF>
>> test
>> .
250 2.6.0 <9438b259-e0ba-4a92-a280-ae1902159df4@[mailserver]> Queued mail for delivery

Author Comment

ID: 26094617
Firstly the message was archived by the Intelligent Message Filtering system and then deleted by the same system, all as per the Message Tracking Centre.

The only type of SPF filtering we have is within exchange itself and that is Sender ID Filtering, which is set to Accept the message if it fails and process it with anti-spam.

Accepted Solution

Cromwellhospital earned 0 total points
ID: 26208710
I've since recreated the temp tables and this appears to have resolved the problem

Featured Post

Creating Active Directory Users from a Text File

If your organization has a need to mass-create AD user accounts, watch this video to see how its done without the need for scripting or other unnecessary complexities.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Mailbox Corruption is a nightmare every Exchange DBA wishes he never has. Recovering from it can be super-hectic if not entirely futile. And though techniques like the New-MailboxRepairRequest cmdlet have been designed to help with fixing minor corr…
There can be many situations demanding the conversion of Outlook OST files to PST format and as such, there is no shortage of automated tools to perform this conversion. However, what makes Stellar OST to PST converter stand above the rest? Let us e…
To show how to generate a certificate request in Exchange 2013. We show this process by using the Exchange Admin Center. Log into Exchange Admin Center.:  First we need to log into the Exchange Admin Center. Navigate to the Servers >> Certificates…
A short tutorial showing how to set up an email signature in Outlook on the Web (previously known as OWA). For free email signatures designs, visit https://www.mail-signatures.com/articles/signature-templates/?sts=6651 If you want to manage em…
Suggested Courses

834 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question