MS Exchange have problems resending to MTAs using greylisting

Today when restarting my Small Business Server 2003 SP2 (SBS2003SP2) I suddenly recieved about 40 DNRs and they were related to GreyListing

Examples:
You do not have permission to send to this recipient. For assistance, contact your system administrator.
mail .*****.com #4.7.1 smtp;450 4.7.1 user@*****.dk: Recipient address rejected: Greylisted, see http://isg.ee.ethz.ch/tools/postgrey/help/*****.dk.html/mail

The e-mail system was unable to deliver the message, but did not report a specific reason. Check the address and try again. If it still fails, contact your system administrator.
mail .*****.com #4.0.0 smtp;451 user@*****.com: MTA says no./mail

You do not have permission to send to this recipient. For assistance, contact your system administrator.
mail .*****.com #4.7.1 smtp;451 4.7.1 Greylisting in action, please come back in 00:01:00/mail
mail .*****.com #4.7.1 smtp;451 4.7.1 message delayed, see http://www.greylisting.org ; Please try again later/mail
mail .*****.com #4.7.1 smtp;450 4.7.1 user@*****.dk: Recipient address rejected: Greylisted for 300 seconds/mail

I did some googleling and found that:
“On a Microsoft Windows Server 2003-based SMTP gateway server, some messages may unexpectedly remain in the queue folder until the SMTP service is restarted. After the SMTP service is restarted, all idle messages in the queue folder are processed correctly. Specifically, the idle messages are delivered, or non-delivery report (NDR) messages are sent to the mail sender. Therefore, the mail sender may receive an NDR message several days or even several weeks after the sender sends a message.”

To Fix this problem you can either:

Solution A: Apply Microsoft hotfix
On a Windows Server 2003-based SMTP gateway server, some messages may remain in the queue folder until the SMTP service is restarted

or

Solution B: Restart the Exchange service
Put these two lines into a .cmd file and run it as a “Scheduled Task” every 24hrs
net stop smtpsvc
net start smtpsvc

net stop smtpsvc - net start smtpsvc

or

Solution C: Use your ISPs Smart Host
Configure Exchange 2003 SMTP connector with ISP SMTP server information.

or

Solution D: Edit the registry
Create the key (looks like a folder though ;) ) “Queuing” under
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SMTPSVC\
Then create the DWORD value “GlitchRetrySeconds” and set it to 60

Exchange GlitchRetrySeconds Key

Other links talking about the problem:
microsoft.public.exchange.admin

Update
It also might be a good idea to install Microsoft Updates
Microsoft Updates to recieve all the Exchange updates available!

4 Responses to “MS Exchange have problems resending to MTAs using greylisting”

  1. Pips says:

    Brilliant… this just started happening and you’re different options helped. Also, I have asked microsoft for the patch.

  2. ACC says:

    Thanks for the tips. However, the MS hotfix you link to in Solution A says the following:

    “This article does not apply to Windows 2003 servers that are running Exchange 2000 or Exchange 2003. This article applies only to Windows Servers that are running the SMTP Service without Exchange 2000 or Exchange 2003.”

    So it does NOT apply to Exchange.
    I will give the others a try though.

  3. Erwin Craps says:

    According to other websites the “GlitchRetrySeconds” should be in HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SMTPSVC\Queuing

  4. Erwin Craps says:

    and it should definitly be higher than 60. Inoticed greylist of 120 seconds, so mine is set to 350.

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