835734 Many unexpected outbound e-mail messages appear in the SMTP queue in
http://support.microsoft.com/?id=835734  [that link not quite live as of 12:45 on Friday… should be shortly though….]

Download details: Update for Windows Small Business Server 2003: KB 835734:

There is a problem with how the POP3 connector processes certain messages downloaded from a POP3 server. This problem could result in the POP3 connector accidentally re-sending certain messages to recipients who are not part of the SBS server e-mail domain.
This may happen only in the cases where the POP3 connector is used to download mail from an external POP account. Customers using Exchange to host their mail internally will not experience this problem. This update resolves this issue.
All SBS customers are encouraged to install this update.


16 Responses to If you are using the POP Connector in SBS 2003 – Get this patch

  1. Chris hawke says:

    Way to late for this one MS After sending out 100,000s of emails last year – I did many a search at MS and the wider web to see if I could find if this was a MS bug or a setup thing and finally bought a 3rd party POP connector, which is great as it cheacks every minute.

    This is the one very weak link in SBS and really needs some time spent on improving it.

    But thanks for pointing it out.


  2. Susan says:

    Charles Anthe notes in his blog entry that the opportunity for relay is small. Are you sure you are not talking about SBS 2000? As that did indeed [and still does] have a potential for relay when using a global pop collector.


  3. Mike says:

    I installed the patch. SBS is still sending out NDRs for addresses that it shouldn’t. What should I do?

  4. A happy patcher says:

    Thanks for that link – amazing how easy it was to find the answer in google and not in M$’s website !

  5. Paul - Iwant to go to bed now but... says:

    Ok – I saw this problem about 8 months ago and it looked like the POP3 route was opening the server up to spam through – I had to kill off that link and make the client move over to true SMTP feed from their domain, but that another story.

    I have just picked another client with SBS2003 and they need to use POP3 collection for a while yet – they fell foul of the problem today and I have just managed to applythe fix but to do so I had to stop the SMTP Connector so that I could swim against the tide of emails coming out on their broadband link. Now all I need to do is delete 5000 odd queued outbound emails – does anyone know a quick way to delete all of them with out having to open each queue? Any suggestions would be gratefully received. Kind regards. Paul UK

  6. Jamie says:

    This problem can get huge – I work for an ISP and often have to sort out issues where this particular flaw in SBS 2003 creates email floods of up to tens of millions of duplicate emails in a day or two – a major problem for any email system and worse if you have an attachment! I’ve written a report about the problem I send to our customers – anyone who wants a copy email snugjam@gmail.com.

  7. Sean says:

    Has anybody noticed the POP3 Connector pounds the hell out of the ISP’s Email server? I have only 10-12 accounts getting POPped every 15 min. ALL THE ACCOUNTS try to connect within seconds. I’m getting 1035 Errors and my ISP thinks I may be flooding their server with connection attempts.

    Any thoughts?


  8. Susan says:

    Yeah either move to a global pop box or full SMTP with that many mailboxes

  9. Pieter Post says:

    Where can i find the SBS2K pop3 collector patch?

    Ik cant find it anywhere

  10. Susan says:

    Sir? The link is right at the top of this very page


  11. Pieter Post says:

    Unfortunately this patch only seems to work in SBS2003. I need the SBS2000 patch, because I have the same problems.

  12. Susan says:

    SBS 2000 didn’t have that issue… you must have some other problem then.

    No it would duplicate emails on bcc’s but that’s a known issue with pop… don’t use it or move to MX/SMTP or use Popbeamer.

  13. Tim Wetzel says:

    We’ve got 4 POP mailboxes with Expedient (who host our web site) and use Comcast as our cable broadband ISP. Since we went from Server 2000 to SBS 2003 the POP3 Connector has been a constant problem. We get anywhere from 10 to 60 errors a day, mostly the sequence of events 1035 (referencing error 11004), 1023, then 1019. I’ve tried quite a few things but can’t get rid of these errors. Our ISP has no suggestions. Both hotfixes 835734 and 833992 have already been applied but the problem continues. Anybody know how to solve this? Thanks, Tim Wetzel

  14. James Field says:

    I seem to have two SBS installations that have many duplicated emails, but inside the exchange organisation. not always, but often each user might have 2-8 of the same message, could this issue be related to this patch? hmmmm…..

  15. Jamie says:

    The report I mentioned in my earlier post can now be found here – http://www.sbslinks.com/popconnector.htm

  16. Kayton Knax says:

    RE: Paul UK, just delete the badmail folder, and create a new one

    RE: Google search ndr’s theres an option to turn them off, and you dont need to send them anyway, the server that sent the email will deliver an ndr