Skip to page contentSkip to chat
ServiceNow support
    • Community
      Ask questions, give advice, and connect with fellow ServiceNow professionals.
      Developer
      Build, test, and deploy applications
      Documentation
      Find detailed information about ServiceNow products, apps, features, and releases.
      Impact
      Accelerate ROI and amplify your expertise.
      Learning
      Build skills with instructor-led and online training.
      Partner
      Grow your business with promotions, news, and marketing tools
      ServiceNow
      Learn about ServiceNow products & solutions.
      Store
      Download certified apps and integrations that complement ServiceNow.
      Support
      Manage your instances, access self-help, and get technical support.
Emails to incidents come in as winmail.dat attachments - Support and Troubleshooting
  • >
  • Knowledge Base
  • >
  • Support and Troubleshooting (Knowledge Base)
  • >
  • Emails to incidents come in as winmail.dat attachments
KB0529478

Emails to incidents come in as winmail.dat attachments


15693 Views Last updated : Apr 30, 2024 public Copy Permalink English (Original)
  • English (Original)
  • Japanese
KB Summary by Now Assist

Issue

Symptom
  • Inbound Email arrives and processes, producing an empty incident record containing an attachment named 'winmail.dat'.
  • Inbound email arrives and when ignored, an attachment named 'winmail.dat' is present on the sys_email record.
  • Inbound email arrives and some or all expected attachments (such as a screenshot, document, spreadsheet) are not present, but instead an attachment named 'winmail.dat' is present. 
What is 'winmail.dat'?

Microsoft products (e.g, via Outlook, Exchange, Outlook365) can send email using Microsoft's proprietary Transport Neutral Encapsulation Format (TNEF) format, which is the winmail.dat package. This format might typically be configured for use internally within a company using Microsoft-only mail environment. From Microsoft:

"TNEF, also known as the Transport Neutral Encapsulation Format, Outlook Rich Text Format, or Exchange Rich Text Format, is a Microsoft-specific format for encapsulating MAPI message properties. All versions of Outlook fully support TNEF. Outlook on the web (formerly known as Outlook Web App) translates TNEF into MAPI and displays the formatted messages. Other email clients that don't support TNEF typically display TNEF formatted messages as plain text messages with Winmail.dat or Win.dat attachments."

In this format, the mail message content and attachments normally expected with the MIME email are instead assembled so that all (or most of) the message and attachments are packaged inside a single MIME attachment "winmail.dat". For more information about the TNEF format see Microsoft's Exchange and Outlook Message Formats documentation.

The ServiceNow platform supports standard MIME emails, and does not have functionality to parse TNEF. It therefore treats this particular 'winmail.dat' MIME attachment no differently than other attachments, such as a document or spreadsheet.

Can a 'winmail.dat' attachment be created by the instance?

No. The ServiceNow platform contains no functionality that generates this file as an attachment on an email.

Can a 'winmail.dat' attachment be read and processed by the instance?

No. The ServiceNow platform contains no functionality that parses the TNEF format.

Does the ServiceNow email infrastructure create 'winmail.dat' files?

No. The ServiceNow inbound email infrastructure does not generate these files.

Release

All ServiceNow product families exhibit this behavior.

Cause

This issue is caused by settings in the sender email environment, either Exchange mail server or Outlook.

Resolution

ServiceNow Workarounds

There are no options or workarounds in the ServiceNow platform or in the ServiceNow mail infrastructure to convert Microsoft's TNEF into a standard MIME email. ServiceNow recommends you work with your email administrator to configure your Exchange server to not send TNEF-formatted emails to external domains. (Or at least ensure this is configured specifically for your ServiceNow instance email addresses.)

Alternatively you may configure the instance to connect the your own email server. The Exchange mailbox server will present the correct format of the emails to the instance if the instance connects to the Exchange server as a client.

Microsoft Documentation

PLEASE NOTE: The following are examples and are not guaranteed to be appropriate for the latest versions of MicroSoft products , for the most up to date details on the configuration ALWAYS consult the MicroSoft documentation or your email administrator.

Here are two current Microsoft documentation links about this topic that may be of assistance. As Microsoft has myriad mail products and versions, and also uses multiple user-facing names for the TNEF format, ServiceNow cannot guarantee these documentation links and provided information apply to your specific product or version. Therefore, if you have questions about how to configure your specific Exchange or Outlook settings, please work with your email administrator or Microsoft support.

  • Content Conversion
  • TNEF Conversion Options
Example in Microsoft Exchange 2010:
  1. Log in to your Exchange Server 2010 by opening the Exchange Management Console (EMC).
  2. Expand Microsoft Exchange On-Premise…
  3. Expand Recipient Configuration.
  4. Select Mail Contact.
  5. Find the contact that represents your ServiceNow instance email (e.g., the one that sends emails to <instancename>@service-now.com).
  6. In our example, we will assume the contact is named Marketing Requests (yours will be named differently).
  7. Open Marketing Requests Properties.
  8. Select the General tab.
  9. In the Use MAPI rich text format field, select Never (as shown below).
  10. Click OK.

Marketing Requests Properties




The world works with ServiceNow.

Sign in for more! There's more content available only to authenticated users Sign in for more!
Did this KB article help you?
Did this KB article help you?

How would you rate your Now Support digital experience?

*

Very unsatisfied

Unsatisfied

Neutral

Satisfied

Very satisfied

Very unsatisfied

Unsatisfied

Neutral

Satisfied

Very satisfied

What can we improve? Please select all that apply.

What are we doing well? Please select all that apply.

Tell us more

*

Do you expect a response from this feedback?

  • Terms and conditions
  • Privacy statement
  • GDPR
  • Cookie policy
  • © 2025 ServiceNow. All rights reserved.