Mails got delivered 3 times in SharePoint enabled discussion board when using an automatic rule in Lotus Notes 7.0.3Mails got delivered 3 times when using an automatic rule in Lotus Notes 7.0.3

Today we encountered a strange issue sending emails to SharePoint. This is the configuration:

  1. A Incoming Email enabled discussion board (disboard@collab.company.com)

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  2. A Lotus Notes mailbox (mailbox@company.com) Email Client with a rule to forward ALL documents to the Discussion board, hence auto-forward everything to disboard@collab.company.com
     

When we send an email from Lotus Notes directly to the discussion board, it worked perfect. The mail is delivered once and displayed like it should be.
When we use the forwarding rule in Lotus Notes, the (forwarded) email is delivered 3 times as you can also see in the screenshot.alt

At this point I was puzzled and started troubleshooting. To test the pure email forwarding functionality, I created a extra forwarder for all documents to my @hotmail.com email address. This worked fine, the (forwarded) email was delivered once into my hotmail inbox. But on the SharePoint site, these mails were delivered 3 times. I noticed when I opened the "triple entries" that the subject had another identifier.

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One of the other 2 subjects displayed nothing extra, and the second had 1736 attached to its "subject".

Of course I was thinking about issues with this forwarding mechanism, and more specific the communication between the SMTP servers,(hence the Domino server and the SMTP connecter of the IIS servers) so I decided to do extra test so I can exclude (or point out) SharePoint as the cause of this issue.
I created a email enabled Document library. When I initiated tests to this Email enabled document library, the test results were all as they should be, even when using the auto –forward rule from Lotus Notes to this Email enable Document library. The email was delivered to the SharePoint Document Library once.

So my first thought of this being a problem with the Domino server got redirected to SharePoint, more specific the settings of my Email enabled discussion board. I compared t
As I noticed when sending a mail directly to the Email Enabled Discussion Board, the original email was saved as an attachment. The emails that appeared 3 times, did not had any attachments, except the original email who got attached to the item….

So, after changing the Save original email setting to NO, it worked just fine.

I tried to create a schema of this, so It would be a little more easy to understand:

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