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Sniffer-a K9 on Outlook

Lets have a quick look at a unique feature of Outlook-Sniffer !!!!

Have you ever encountered an occasion where you received a meeting request, and you forgot to respond to it, but you’d get a meeting reminder and then you hurry up preparing the reports in 15 min and running to the meeting? If your answer is YES, then thank Outlook “Sniffer”.

Very often I have been asked this question and so, I decided to pen down my knowledge about it as not much of information about it is found over the internet. Now let’s see who this k9 of Outlook is.

Outlook Inbox “Sniffer” is (I should say that it is a mandatory) feature available in Outlook 2000 and above. This is a part of the MAPI process which won’t work unless or until the integrated MAPI profile is idle. Basically, it “Sniffs” each and every item that you receive in your inbox and actions on them depending on the type of the message. Whenever you receive a

  • Meeting requests
  • Meeting response
  • “Message recall” item
  • a regular e-mail with a reminder
  • Updates to tasks
  • Voting response
  • Read/Delivery receipts

Our dog sniffs and actions upon it. So, whenever you receive a

  • Meeting request, the meeting is placed as tentative appointment in your calendar, till you action upon it.
  • Meeting response, the meeting is updated with the details.
  • Update to tasks are update in the respective tasks
  • A regular e-mail with a reminder, a reminder is set and you’ll be reminded
  • Voting Button’s response, the response is classified and added to the original voting item
  • Read/Deliver Receipts adds to the tracking details of the original message.

If you start searching the last three options in your Outlook 2003, then be advised that you will never find it. For it is a feature of Outlook 2007 and above.


Me: He.. he.. he.. I just wanted to explain in detail about it.

When a sender attempts to recall a message, and if the recalled message is in the Inbox of the recipients, unread, then the message is deleted and the sender receives a status message of “Success”(Remember Sniffer works ONLY when the MAPI process is idle. So might not work always). But if the recipient is either a little bit intelligent and would have thought that the Sender would recall the message and moved the original message to another folder or would have had better ways of managing e-mails using rules, then you might never receive a  message with recall status. Remember? I said Sniffer works ONLY on the items that you receive in your Inbox? So, no use complaining your Exchange server that you never received the recall status message.

If the recalled message is either read, or is in another folder other than the folder where you have the “Message recall”, then it would fail when you open it.

You: “Now what if I feel that my dog’s nose isn’t helping?”

Me: Well, then check the following things:

  1. Is the item really in Inbox? Remember the fact that Sniffer works ONLY on the items in inbox.
  2. Do you have any Outlook Add In, which might keep the MAPI process, busy? Remember the fact that Sniffer works ONLY when the MAPI is idle (like me at office!!)
  3. Probably, polling intervals might be set for your sniffers. The registry values under the key “HKEY_Current_User/Software/Microsoft/Office/11.0/Outlook/Options/General” (In case of OL 2007, HKEY_Current_User/Software/Microsoft/Office/12.0/Outlook/Options/General”) would define this.
    • AutoProcessIdleTime: Defines the idle time after which sniffer would start. (Default would be 30000 if it is not defined here)
    • AutoProcessIdleTimeMax: Defines the time that the Sniffer would wait to check the status of MAPI, if in the last attempt, the MAPI is busy.(Default would be 60000 if not defined)

Remember that both the settings are in Milliseconds (1/1000th of a second) and setting up a lesser value would cause the sniffer to run continuously, adversely affecting Outlook’s performance.

  1. Any other computer has the user’s Outlook configured with a MAPI profile? Only a Sniff Owner can run sniffs in a user’s mailbox (pretty much, to avoid conflicts). Try running Outlook with “/sniff” switch to force the sniffer to work with the current profile. If you want the current Outlook profile to be the permanent owner, then start running Outlook with “/cleansniff” which would probably delete and re-create the sniff information. The MAPI attribute “PR_PROCESSED” on a mailbox item would say if an item is sniffed or not. If it is set to “True”, then the message would have been sniffed. You can view this attribute using MFCMapi tool.
  2. Is the Outlook, not set to be sensitive for few item types? Check the same in Tools-> Options->Email options->Tracking Options.(“Process requests and responses on arrival” and “Process Receipts on arrival” are the options that you might want to look into)
  3. If nothing above works, then there could be some Outlook Add in which might be “Sniffing” the items. Try starting Outlook without add ins.
  4. Try posting your problem in the comments section and let us see if we can help you! J

You: “Wow!! But what happens in case I use Microsoft Entourage to receive e-mails from the Exchange Server?”

Me: Mac doesn’t support the RPC protocol which is required for a MAPI client to function. So, a MAPI client in Mac is fairly possible.

This is pretty much all that I know about the k9 unit. Happy or angry? Please reflect your feelings as comments below


4 Responses to “Sniffer-a K9 on Outlook”

  1. Ram Says:

    well is should say…thats a deep explanation on sniffer. thanks..!!!

  2. Praveen Says:

    Hey !! well covered… Nice article…

    small query, what will happen if the user has a blackbery. BB processes the request before sniffer comes into picture.

  3. Muthukumar P Says:

    Thanks Praveen! 🙂

    If you’re using BES, as we are aware, BB server retrieves e-mails from Exchange using MAPI. So, the sniffer is still applicable.

  4. TechGuy Says:

    Excellent idea to write a blog post about this topic, as there doesn’t seem to be too much information on internet. I found it very useful.

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