Stopping Outlook from sending unwanted .dat attachments

The Ms Outlook applicationth has over the years has gained a lot of appreciation from its users and has drawn few brickbats too. A persistent complain that has followed Outlook application through the years is its propensity to include unknown .dat attachments like winmail.dat in emails. When an email containing such attachments reaches its destination its receiver cannot open these attachments and is left wondering why they have been sent. The issue is in fact caused by a facet of Outlook wherein it uses winmail.dat file to contain formatting instructions for emails sent in the RTF format. Now if this email is accessed with a different email client, the proprietary Outlook format is not resolved and .dat attachments are displayed. Now if you are looking to avoid the issue you should send emails in plain text or html formats.


Configuring Outlook Mail Options to Avoid .dat attachments

  1. Go to the File tab in Outlook and then click on Options
  2. Next you need to go to the Mail group tab
  3. Under the Mail category you need to go to the choice mentioning “Compose in this message format”. Choose either HTML or plain text here
  4. Next you also need to select the option which mentions that when sending emails to internet recipient, RTF formats emails would be converted to HTML.
  5. Hit the Ok button to save your preferences


Dealing with exceptions

At some point of time you may still receive a complaint from your email recipient that you have sent .dat attachments to them. This may occur as individual settings on a particular message can possibly override the default settings. Given the scenario you would have to alter the settings for that specific contact. To do so you need to first trace out the specific email id from the Contact list and then right click on it. From the right click menu, go to Outlook properties. Next ensure that choice under Internet format is set to plain text only. While you can also choose the option where Outlook will decide the format, choosing plain text can assuredly eliminate the issue from cropping up again.


Limit the Size of PST files in Outlook to Avoid Outlook Crashes

The Ms Outlook application is know to crash at times and a majority of such crashes can be attributed to PST errors. Such errors are more likely to crop up whenever the size of the underlying PST files run into few gigabytes. In older versions of Outlook, the moment 2GB limit was reached, Outlook application started to crash. Irrespective of the version, limiting the size of the PST files is a great idea to keep the Outlook application in shape. With the help of DataNumen Outlook Repair application you can split large PST files within seconds. Moreover this powerful pst repair tool proves handy in recovering data from corrupted Outlook files and is effective on virtually any media type.


Author Introduction:

Alan Chen is President & Chairman of DataNumen, Inc., which is the world leader in data recovery technologies, including sql recovery and outlook repair software products. For more information visit

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