Solving the dreaded winmail.dat issue in Lotus Notes

So your users are getting these "winmail.dat" attachments in Lotus Notes and can't open them, nor can they see any special formatting that the sender had added (and the sender is ALWAYS from Outlook).

Quick solution:

  1. Make sure you are on the latest fix pack of Lotus Domino. That should be 6.5.6, 7.0.3, 8.0.2, or 8.5.x.
  2. Open Lotus Domino Administrator and issue the following commands (copy and paste one at a time):
Set config TNEFKeepAttachment=1 
set config TNEFEnableConversion=1

tell router update config

The problem is that Outlook is tunneling rich text formatted information in an attachment through the Internet using a proprietary format (concocted by Microsoft), rather than MIME (an Internet standard). It (wrongly) assumes the recipient is also using Outlook.

Microsoft opened up the format so other vendors could read the content, and IBM and other vendors have included that ability in later patches. You should not have this problem at all on Domino 8.5x, but will have to issue these commands on older versions of the server.

This and several other little "gotchas" can be easily resolved if you know where to go. If your organization does not have a dedicated Domino admin, it may benefit from having someone come in and help on an ad-hoc basis. Just contact us for more info. If you need help upgrading we (Strongback Consulting) offer upgrade services on all platforms (System i, Unix, Windows, Linux).

Also, if you are not on the latest and greatest of Notes/Domino, there are some features you are missing out on. Mainly the newest social features built into the product. SlashdotMedia has a great article on how email is going more social and not just inbox-centric.
Read the Whitepaper: Cloud, Collaboration and Communication: What's top of IT Leaders' Minds?
If you are still using a version of Lotus Notes/Domino earlier than version 8, you are about 5 years left in the dust on technology. The product has changed considerably in version 9 with the IBM Notes Social Edition.

Labels: , ,