Please help....winmail.dat issue...slowly going insane.....

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Outlook version
Outlook 2010 32 bit
Email Account
Exchange Server
Ok, Heres my problem...

I am using QuickBooks accounting system to produce pdf contracts for my business. I click send and it opens Outlook and sends my email and attachment.

Some of my customers (not all) complain that they only receive a winmail.dat file instead of the attachment. I understand that its because Outlook is sending the files as 'rich text' but I can't seem to fix it.

Heres what I've tried so far....

File>options>mail>message format> convert to plain text format. - It still sends as winmail.dat

Contacts>'click on individual contact'>double click on email address>more options>outlook properties>'changed 'let Outlook decide' to 'send plain text only'

-This, I had high hopes for, as it worked on my none office laptop when sending a pdf file but from my office laptop it STILL it sends as a winmail.dat file!

This is about the time I started to bang my head against the desk.

I am wondering whether the problem is sending it through Quickbooks but through trial and error I've worked out that It's not Quickbooks that is the problem. Sending the attachment straight from Outlook still results in the winmail.dat file.

On a test email I've found that its not a problem opening the attachments on a desktop email client, the problem is when a customer (as they often need to) tries to open it on a mobile device, but again some have this problem when others don't.

Does anyone know where the problem lies? Is there an obvious thing that I'm missing??

Diane Poremsky

Senior Member
Outlook version
Outlook 2016 32 bit
Email Account
Office 365 Exchange
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