?
Solved

winmail.dat attachments

Posted on 2009-02-10
9
Medium Priority
?
666 Views
Last Modified: 2013-11-22
Hi,
I have a client that has begun having issues sending e-mail attachments, which they send a lot of. It seems that this issue started suddenly about 2 weeks ago. The e-mail client settings (smtp server and other account settings) have remained stable for ~3 years, as well as the AV software, which is CA Security Center. As far as I can tell the CA software is not scanning outgoing mail, or at least there is no setting to do so.

Some recipients are receiving a "winmail.dat" attachment instead of the original .pdf or .doc attachment. It seems the affected recipients are those that are not using Outlook as their e-mail client. Can someone tell me what is going on here, and where it is going on at?

I am in the process of changing the SMTP server in our Outlook clients from our ISP (Time Warner cable) to smtpauth.hosting.earthlink.net (our domain host's smtp server), to see if this eliminates the issue.

Thanks,
Bill
0
Comment
Question by:westone
  • 3
  • 3
  • 2
  • +1
9 Comments
 
LVL 8

Expert Comment

by:JustWorking
ID: 23608028
Not sure what version of Outlook you are using but..it is probably pretty old:
Prevent Winmail.dat Attachments from Being Sent in Outlook
To prevent Outlook from attaching winmail.dat when you send an email:

Select Tools | Options... from the menu.
Go to the Mail Format tab.
Under Compose in this message format:, make sure either HTML or Plain Text is selected.
Click Internet Format.
Make sure either Convert to Plain Text format or Convert to HTML format is selected under When sending Outlook Rich Text messages to Internet recipients, use this format:
Click OK.
Click OK again.

Disabe Winmail.dat Stubbornly Going to Particular Recipients No Matter the Default
The standard settings for outgoing mail formats in Outlook can be overridden per email address. So, on a per case basis  when somebody complains about an inexplicable "Winmail.dat" attachment after you have made all the right settings changes , you may have to reset the format for individual addresses:

Search for the desired contact in your Outlook Contacts.
Double-click the contact's email address.
Alternatively, click on the desired email address with the right mouse button and select Outlook Properties... from the menu.
Make sure either Let Outlook decide the best sending format or Send Plain Text only is selected under Internet format:.
Click OK.
0
 
LVL 97

Accepted Solution

by:
war1 earned 2000 total points
ID: 23608088
Hello westone,

Make sure you have the latest updates and hotfixes for your version of Outlook.

Winmail.dat file is usually cause by Outlook non-standard HTML format. So those not using Outlook will get the email with format in winmail.dat attachment.  Send in Plain Text, and you will be sure recipient will get the email correctly.

Hope this helps!
war1
0
 
LVL 2

Expert Comment

by:Silly013
ID: 23608669
This could be your anti-virus as well > happened before with Trendmicro... I don't remember the exact settings now but you can check if you have one.
0
Evaluating UTMs? Here's what you need to know!

Evaluating a UTM appliance and vendor can prove to be an overwhelming exercise.  How can you make sure that you're getting the security that your organization needs without breaking the bank? Check out our UTM Buyer's Guide for more information on what you should be looking for!

 
LVL 2

Expert Comment

by:Silly013
ID: 23608695
0
 

Author Comment

by:westone
ID: 23610682
We are using Outlook 2007, and Microsoft Update runs every day. Silly, your link comes close, except we are already using the HTML format. I have changed it to plain text per this info: http://facstaff.gpc.edu/~jbenson/resource/winmail.htm#default 
0
 
LVL 97

Expert Comment

by:war1
ID: 23613711
westone, when run in Plain Text mode, does the winmail.dat attachment go away?
0
 

Author Comment

by:westone
ID: 23624580
Yes.
0
 
LVL 97

Expert Comment

by:war1
ID: 23624700
westone,

I suggested running in Plain Text mode in my first comment Date:02.10.2009 at 07:45PM PST  Did you see it?
0
 

Author Comment

by:westone
ID: 23625868
DOH! No, I did not and I apologize. In my defense, over the last 10 days my personal life has gone to hell in a handbasket and I am distracted. It was the HTML formatting that was causing this issue. Thanks.
0

Featured Post

Free Tool: Port Scanner

Check which ports are open to the outside world. Helps make sure that your firewall rules are working as intended.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

With so many activities to perform, Exchange administrators are always busy in organizations. If everything, including Exchange Servers, Outlook clients, and Office 365 accounts work without any issues, they can sit and relax. But unfortunately, it…
Mailbox Corruption is a nightmare every Exchange DBA wishes he never has. Recovering from it can be super-hectic if not entirely futile. And though techniques like the New-MailboxRepairRequest cmdlet have been designed to help with fixing minor corr…
The basic steps you have just learned will be implemented in this video. The basic steps are shown to configure an Exchange DAG in a live working Exchange Server Environment and manage the same (Exchange Server 2010 Software is used in a Windows Ser…
Is your OST file inaccessible, Need to transfer OST file from one computer to another? Want to convert OST file to PST? If the answer to any of the above question is yes, then look no further. With the help of Stellar OST to PST Converter, you can e…

621 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question