• Outlook User
  • New Outlook app
  • Outlook.com
  • Outlook Mac
  • Outlook & iCloud
  • Developer
  • Microsoft 365 Admin
    • Common Problems
    • Microsoft 365
    • Outlook BCM
    • Utilities & Addins

Can't Accept or Decline Tasks

Slipstick Systems

› Outlook › Tasks › Can’t Accept or Decline Tasks

Last reviewed on March 8, 2022     10 Comments

Applies to: Outlook 2010

When you send tasks to someone, the recipients needs to use Outlook to accept or decline the task. If the recipient receives a plain text message, your mail server is removing the TNEF data that tells Outlook it's a task. If you are using Exchange server, the Administrator may have the server configured to remove the data when messages are sent to the Internet, as non-Outlook users will see a winmail.dat attachment.

Outlook 2010

We're seeing reports from users that sending Task invitations through an IMAP account is "breaking" the accept and decline buttons.

The workaround: Switch to a POP3 account, if supported.

Outlook 2003

If you discover you are unable to accept or decline tasks, the probable cause is a failed update.

The Security Update for Outlook 2003, released on January 10, 2006 and described in Knowledge Base article 892843, is reported to cause problems when accepting assigned tasks or updating completed tasks on the sender's tasks list. This security update may also cause some VBA and scripts to fail.

Not everyone who installs this update is affected and later updates may fix it, so go ahead and install it, but if you experience problems opening or accepting tasks, with tasks updates, you'll need to uninstall the update. You can do this through Control Panel, Add and Remove Programs.

Those who have problems have two or more copies of this update installed for some reason and there doesn't seem to be a problem if only one copy of the patch is installed so it only affects a small percentage of Outlook users. Keep in mind that removing the update will not fix tasks that were affected, but all new tasks should work correctly in the future.

To uninstall the update(s), go to Add/Remove Programs and click the "show updates" checkbox. The update should be listed under the entry for Microsoft Office 2003. Click Remove to uninstall. If tasks work correctly, you can reinstall the update along with the hotfix found in KB 913695, if you desire. As long as only one copy is installed it should work as expected.

More Information

Microsoft Security Bulletin MS06-003 - Critical Vulnerability in TNEF Decoding in Microsoft Outlook and Microsoft Exchange Could Allow Remote Code Execution (902412)

Can't Accept or Decline Tasks was last modified: March 8th, 2022 by Diane Poremsky

Related Posts:

  • Outlook crashes when viewing HTML Messages
  • Outlook Only Starts in Safe Mode?
  • Outlook.com & Outlook 2010 Troubleshooting
  • Understanding Outlook 2013 Updates

About Diane Poremsky

A Microsoft Outlook Most Valuable Professional (MVP) since 1999, Diane is the author of several books, including Outlook 2013 Absolute Beginners Book. She also created video training CDs and online training classes for Microsoft Outlook. You can find her helping people online in Outlook Forums as well as in the Microsoft Answers and TechNet forums.

Subscribe
Notify of
10 Comments
newest
oldest most voted
Inline Feedbacks
View all comments

daniel
April 20, 2017 1:42 am

Hi - it seems we are experiencing this issue with Office 365 + Outlook 2016 whereby the Accept / Decline options are not visible and the formatting of the email only displays 1/3 of the email. Has anyone had any success in resolving this ?

Please note : No auto enabled signature applications are running for this particular account.

1
0
Reply
Diane Poremsky
Author
Reply to  daniel
May 25, 2017 8:04 pm

Have the latest updates fixed the problem? There were some formatting issues in email that were fixed in a recent update.

0
0
Reply
jason
Reply to  Diane Poremsky
February 19, 2018 12:40 pm

Hi Diane. The above is still an ongoing issue. Office 365 and Outlook 2016 and also Outlook web app seem to not be showing the Accept and Decline options for tasks and most times, the assigned tasks don't even show-up in the user Tasks section. Any fixes you think we can try?

2
0
Reply
Diane Poremsky
Author
Reply to  jason
February 19, 2018 10:38 pm

if only some tasks are affected, are they received as tasks or messages?

If the TNEF blob is missing or corrupt the task won't work correctly.

0
0
Reply
Shehu Ibrahim
April 15, 2014 2:02 am

Diane,
I have discovered the problem. It is Gmail account that doesn't allow Assigned Task to run. I have tried with my Cpanel Email accounts and it works. However, this Gmail problem is recent.

Hear this (from Google site)

What's not available...

And finally, there a few features that aren't available in Outlook or Google Apps:

Task delegation. You can't have your assistant manage your tasks as a delegate.

Assigning tasks to others. If you assign a task to someone in Outlook, the assignment doesn't sync with Google Apps. As a result, the task appears to be owned by that person in your local Outlook client, but the other person won't see the assignment in their account.

0
0
Reply
Shehu Ibrahim
April 15, 2014 1:57 am

Diane,
Am happy to intimate you that I have discover what is my problem. Its Google Aps email (gmail Account) that is the problem. I have tried with my normal Email through Cpanel and it worked correctly.

I also wen to Google site and discover the following statement :

What's not available...

And finally, there a few features that aren't available in Outlook or Google Apps:

Task delegation. You can't have your assistant manage your tasks as a delegate.

Assigning tasks to others. If you assign a task to someone in Outlook, the assignment doesn't sync with Google Apps. As a result, the task appears to be owned by that person in your local Outlook client, but the other person won't see the assignment in their account.

0
0
Reply
Shehu Ibrahim
March 10, 2014 2:52 pm

Thanks for your promptness, I use pop3 type of account.

0
0
Reply
Diane Poremsky
Reply to  Shehu Ibrahim
March 11, 2014 9:08 am

The eml extension indicates it's seen as an Outlook Express or Live Mail message. Are you (or someone) sending the tasks from another outlook? They are being converted to messages when the TNEF data (that tells outlook it's a task) is removed. An Antivirus scanner could be responsible or one of the mail servers involved.

0
0
Reply
Shehu Ibrahim
March 9, 2014 5:51 pm

Having sleepless night I cant resolve "Cant Accept or Decline Tasks" with my outlook. Please help me. I had 2010 MS Outlook installed when I had the problem. I downgraded to 2007 and yet the problem persist. Instead of Task Icon...my task was always received as mail with attachment (file extension .eml) which doesnt make sense.

0
0
Reply
Diane Poremsky
Reply to  Shehu Ibrahim
March 10, 2014 2:04 am

What type of email account do you use?

0
0
Reply

Visit Slipstick Forums.
What's New at Slipstick.com

Latest EMO: Vol. 30 Issue 34

Subscribe to Exchange Messaging Outlook






Support Services

Do you need help setting up Outlook, moving your email to a new computer, migrating or configuring Office 365, or just need some one-on-one assistance?

Our Sponsors

CompanionLink
ReliefJet
  • Popular
  • Latest
  • Week Month All
  • Use Classic Outlook, not New Outlook
  • Mail Templates in Outlook for Windows (and Web)
  • How to Remove the Primary Account from Outlook
  • Reset the New Outlook Profile
  • Disable "Always ask before opening" Dialog
  • Adjusting Outlook's Zoom Setting in Email
  • How to Hide or Delete Outlook's Default Folders
  • This operation has been cancelled due to restrictions
  • Change Outlook's Programmatic Access Options
  • Shared Mailboxes and the Default 'Send From' Account
  • Opt out of Microsoft 365 Companion Apps
  • Mail Templates in Outlook for Windows (and Web)
  • Urban legend: Microsoft Deletes Old Outlook.com Messages
  • Buttons in the New Message Notifications
  • Move Deleted Items to Another Folder Automatically
  • Open Outlook Templates using PowerShell
  • Count and List Folders in Classic Outlook
  • Google Workspace and Outlook with POP Mail
  • Import EML Files into New Outlook
  • Opening PST files in New Outlook
Ajax spinner

Recent Bugs List

Microsoft keeps a running list of issues affecting recently released updates at Fixes or workarounds for recent issues in classic Outlook (Windows).

For new Outlook for Windows: Fixes or workarounds for recent issues in new Outlook for Windows .

Outlook for Mac Recent issues: Fixes or workarounds for recent issues in Outlook for Mac

Outlook.com Recent issues: Fixes or workarounds for recent issues on Outlook.com

Office Update History

Update history for supported Office versions is at Update history for Office

Outlook Suggestions and Feedback

Outlook Feedback covers Outlook as an email client, including Outlook Android, iOS, Mac, and Windows clients, as well as the browser extension (PWA) and Outlook on the web.

Outlook (new) Feedback. Use this for feedback and suggestions for Outlook (new).

Use Outlook.com Feedback for suggestions or feedback about Outlook.com accounts.

Other Microsoft 365 applications and services




New Outlook Articles

Opt out of Microsoft 365 Companion Apps

Mail Templates in Outlook for Windows (and Web)

Urban legend: Microsoft Deletes Old Outlook.com Messages

Buttons in the New Message Notifications

Move Deleted Items to Another Folder Automatically

Open Outlook Templates using PowerShell

Count and List Folders in Classic Outlook

Google Workspace and Outlook with POP Mail

Import EML Files into New Outlook

Opening PST files in New Outlook

Newest Code Samples

Open Outlook Templates using PowerShell

Count and List Folders in Classic Outlook

Insert Word Document into Email using VBA

Warn Before Deleting a Contact

Use PowerShell to Delete Attachments

Remove RE:, FWD:, and Other Prefixes from Subject Line

Change the Mailing Address Using PowerShell

Categorize @Mentioned Messages

Send an Email When You Open Outlook

Delete Old Calendar Events using VBA

Repair PST

Convert an OST to PST

Repair damaged PST file

Repair large PST File

Remove password from PST

Merge Two Data Files

Sync & Share Outlook Data

  • Share Calendar & Contacts
  • Synchronize two computers
  • Sync Calendar and Contacts Using Outlook.com
  • Sync Outlook & Android Devices
  • Sync Google Calendar with Outlook
  • Access Folders in Other Users Mailboxes

Diane Poremsky [Outlook MVP]

Make a donation

Mail Tools

Sending and Retrieval Tools

Mass Mail Tools

Compose Tools

Duplicate Remover Tools

Mail Tools for Outlook

Online Services

Calendar Tools

Schedule Management

Calendar Printing Tools

Calendar Reminder Tools

Calendar Dates & Data

Time and Billing Tools

Meeting Productivity Tools

Duplicate Remover Tools

Productivity

Productivity Tools

Automatic Message Processing Tools

Special Function Automatic Processing Tools

Housekeeping and Message Management

Task Tools

Project and Business Management Tools

Choosing the Folder to Save a Sent Message In

Run Rules on messages after reading

Help & Suggestions

Submit Outlook Feature Requests

Slipstick Support Services

Buy Microsoft 365 Office Software and Services

Visit Slipstick Forums.

What's New at Slipstick.com

Home | Outlook User | Exchange Administrator | Office 365 | Outlook.com | Outlook Developer
Outlook for Mac | Common Problems | Utilities & Addins | Tutorials
Outlook & iCloud Issues | Outlook Apps
EMO Archives | About Slipstick | Slipstick Forums
Submit New or Updated Outlook and Exchange Server Utilities

Send comments using our Feedback page
Copyright © 2025 Slipstick Systems. All rights reserved.
Slipstick Systems is not affiliated with Microsoft Corporation.

:wpds_smile::wpds_grin::wpds_wink::wpds_mrgreen::wpds_neutral::wpds_twisted::wpds_arrow::wpds_shock::wpds_unamused::wpds_cool::wpds_evil::wpds_oops::wpds_razz::wpds_roll::wpds_cry::wpds_eek::wpds_lol::wpds_mad::wpds_sad::wpds_exclamation::wpds_question::wpds_idea::wpds_hmm::wpds_beg::wpds_whew::wpds_chuckle::wpds_silly::wpds_envy::wpds_shutmouth:
wpDiscuz

Sign up for Exchange Messaging Outlook

Our weekly Outlook & Exchange newsletter (bi-weekly during the summer)






Please note: If you subscribed to Exchange Messaging Outlook before August 2019, please re-subscribe.

Never see this message again.

You are going to send email to

Move Comment