Recover & Repair DAT File – Winmail.dat & ATT00001.dat

Written By Nimisha Ramesh

Approved By Mack John

Published On January 3rd, 2017

Reading Time 5 Minutes Reading

How to Recover & Repair DAT File Error in Email Messages

A DAT file is used by many different applications to maintain generic information related to the application. As DAT file is nothing but a data file, therefore, it is generated by various available applications. It stores input or output file containing relevant information rather than storing main information such as program files, code and data structure file. The DAT file creates two data files. One is Text file that stores data in ASCII character form and a user can easily open it in any text editor like notepad. Another is Binary File that stores data information in the binary format (0 or 1). However, when a text or binary file is corrupted, it results in a file with DAT file extension. This article describes ways to recover Winmail.dat file & repair DAT File error easily.

Moreover, the TNEF or Transport Neutral Encapsulation Format is used to for sending a message between the applications through the internet. TNEF is a message that contains plain text or binary format to store information related to the original message. A user can identify the TNEF file with the help of extension i.e. all attachments that have Winmail.dat are TNEF file. Another type of DAT file is the ATT00001.dat file, which is created generally when a client is unable to determine TNEF part of the message. Therefore, in this post, manual methods to recover & repair DAT file error is discussed completely.

Reasons to Recover Corrupted DAT file

Fix Winmail.dat File
This file is mainly created whenever there is an error in message format or configuration settings. For example, an Outlook user sends an attachment with the message and selected rich text format and other user configured his account with the plain text format. Then, the receiver is not able to open emails and there arises need to repair Winmail.dat file & fix DAT file created in an email which will help to recover winmail.dat
Repair ATT00001.dat File
If a user is using Microsoft Exchange Server and adds text after attachments in emails then, Microsoft Exchange Server ignore text after attachments and consider all as attachments. However, the text added after attachments are now converted in attachments with a false name i.e. ATT00001.dat file. Hence you need to Recover DAT File

Manual Methods to Recover & Repair DAT File Error

Depending upon the type of DAT file, a user can select the manual method to repair DAT file error. Different manual methods based on type DAT files are listed below:

Manual Methods to Resolve Winmail.dat Problem

Solution 1: Repair Winmail.dat file by Creating New Recipient List in PAB

One can choose an address in Personal Address Book and select plain text format for those addresses. To create new recipient & fix DAT file list follow the steps given below:

1. First of all, go to Tools and click on Address Book
2. Click on Personal Address book in Shows Names From
3. After that, select the address that a user wants to set as Plain Text and click on Properties from File menu
4. Now, open SMTP General Tab and uncheck the Always send to this recipient in Microsoft Exchange rich text format box and click on OK. This will help you to Repair Winmail.dat file

Solution 2: Recover DAT File by Modifying Rich Text Format Email Setting

A user can repair Winmail.dat file by following the steps mentioned below:

1. In Outlook, click on Options >> Tools >> Mail Format option
2. After that, click on Internet Format
3. Now, from the list of Outlook Rich Text Format, click on either Convert to Plain Text format or Convert to HTML format option which will help to Repair Winmail.dat file.

Solution 3: Modify the Contact Format to Recover DAT File

1. First of all, open Recipient’s Record in the Contacts folder
2. After that, double-click on recipient’s email address
3. Now, click on Email Properties and then, on Send Plain Text option under Internet Format to Repair DAT File Error

Solution 4: Repair DAT file by Changing Outlook Default Message Format

1. Navigate to Tools >> Options >> Mail Format option
2. Select Plain Text in Compose in this message format list and click on OK button

Manual Solutions to Recover ATT00001.dat file

There is no direct manual available to repair ATT00001.dat file. Therefore, it is always suggested use correct method of sending a message along with attachments. It is suggested that before attaching attachment, a user uses text sections to prevent the DAT file issue. If a user is not able to resolve this then, a user can choose an alternative solution to fix DAT file.

Advanced Solution to Recover winmail.dat

If a user is not able to recover DAT file error using any of the manual discussed then, he can go for any third party tool available online to fix DAT file.

Conclusion

There is basically two main type .dat file i.e. Winmail.dat and ATT00001.dat file that a user may face. After understanding the main reason behind the occurrence of DAT file in the message with attachments, we have discussed various manual methods to recover and repair DAT file. A user can choose any of them based on the type of DAT file to Repair Winmail.dat file or ATT00001.dat file.