This error usually occurs while trying to sign-in to Outlook, sending emails, or syncing mails, calendars, or contacts. This happens when Outlook fails to verify the login credentials.<\/p>
In this post, we will try to understand the reasons behind the error 0x80049dd3 in Outlook and see how to fix it.<\/p>
What Causes the Error 0x80049dd3 in Outlook?<\/strong><\/h2>This error can occur in both the classic and the new Outlook desktop applications. The exact cause of the error is still not known. However, it is associated with authentication and sync issues in Outlook, which can occur due to one of the following reasons:<\/p>
\n- Expired or corrupted authentication tokens<\/li>\n\n\n\n
- Session cookie failures<\/li>\n\n\n\n
- Microsoft server-side sync glitches<\/li>\n\n\n\n
- Bugs in the New Outlook interface<\/li>\n\n\n\n
- Corrupt Outlook profile<\/a><\/li>\n<\/ul>
There are some other reasons that may also cause this error, such as:<\/p>
\n- Incorrect Outlook configuration<\/li>\n\n\n\n
- Conflicts with add-ins or external programs<\/li>\n\n\n\n
- Unregistered or missing DLL files<\/li>\n\n\n\n
- Corrupt or incomplete Office installation<\/li>\n\n\n\n
- Corruption in Outlook data file (PST)<\/a><\/li>\n<\/ul>
Troubleshooting Methods to Resolve Outlook Error 0x80049dd3<\/strong><\/h2>When you get the sign-in error prompt, do not click on continue to sign-in. As a way around, close the sign-in prompt by clicking on the close (X<\/strong>) button, instead of continuing. This helps you to access emails in Outlook but it is not a permanent solution. To resolve the error, you can try the below-mentioned troubleshooting methods.<\/p>Method 1 – Repair or Reinstall Outlook (MS Office)<\/h3>
The error 0x80049dd3 may occur if the Outlook program files are damaged or corrupted. In such a case, you can try repairing or reinstalling the Outlook (MS Office) program. To repair the program, follow these steps:<\/strong><\/p>\n- Open the Control Panel and go to Programs > Programs & Features > Uninstall a program<\/strong>.<\/li>\n\n\n\n
- From the list of programs, choose Microsoft Office<\/strong> and click Change<\/strong>.<\/li>\n\n\n\n
- Continue to follow the onscreen prompts to repair Microsoft Office and Outlook.<\/li>\n<\/ul>
If repairing the program didn’t fix the error, you can uninstall MS Office and do a fresh install.<\/p>
Method 2 – Clear Cached Credentials<\/h3>
Outdated or corrupted login tokens\/credentials stored in your system can cause authentication issues in Outlook. In such a case, you can try clearing the cached credentials. To remove the saved credentials, follow these steps:<\/p>
\n- Open Control Panel<\/strong>, click User Accounts<\/strong>, and then click Credential Manager.<\/strong><\/li>\n<\/ul>
![\"Open](\"https:\/\/www.stellarinfo.com\/blog\/wp-content\/uploads\/2025\/08\/Credential-Manager.png\")
<\/figure>\n- In the Credential Managers window, go to Windows Credentials and look for entries related to Outlook <\/strong>and<\/strong> MS Office<\/strong>.<\/li>\n\n\n\n
- Click on the required entry to expand it and then click Remove from Vault <\/strong>or <\/strong>Remove<\/strong>, depending on the Windows version you’re using<\/strong>.<\/li>\n\n\n\n
- After removing the stored credentials, restart Outlook and then try to sign in again when prompted.<\/li>\n<\/ul>
Method 3 – Re-register the DLL File in Windows<\/h3>
Outlook application relies on the Windows DLL file (inetcomm.dll) to perform tasks, like sending\/receiving emails or syncing with servers. If this file is deleted or missing, it can lead to errors when accessing emails. To resolve the issue, you can re-register the inetcomm.dll file in Windows. For this,<\/p>
\n- Open the Run<\/strong> dialog box (click ‘Windows’ + ‘R’ keys together).<\/li>\n\n\n\n
- Next, type regsvr32 inetcomm.dll.<\/li>\n<\/ul>
Method 4 – Create a New Outlook Profile<\/h3>
The Outlook profile contains all the information related to Outlook configuration, email accounts, data files, etc. If the profile gets corrupted or damaged, you may face issues when logging in or accessing the emails or other items in Outlook. If your Outlook profile is corrupted, you can create a new profile<\/a> and replace it with the corrupted one. To do so, follow these steps:<\/p>\n- Open the Control Panel on your system. Click User Accounts<\/strong> and then click Mail<\/strong>.<\/li>\n<\/ul>
![\"Click](\"https:\/\/www.stellarinfo.com\/blog\/wp-content\/uploads\/2025\/08\/User-Accounts-1024x538.png\")
<\/figure>\n- In the Mail Setup-Outlook<\/strong> window, select Show Profiles<\/strong> and then click Add<\/strong>.<\/li>\n\n\n\n
- In the Profile Name<\/strong> field, enter the name you want to use for your new profile.<\/li>\n\n\n\n
- On the Auto Account Setup<\/strong> window, under E-mail Account<\/strong>, enter Your Name<\/strong>, E-mail Address<\/strong>, and Password<\/strong>, and then click Next<\/strong> > Finish<\/strong>.<\/li>\n\n\n\n
- You can check the new profile under the General<\/strong> tab in the Mail<\/strong> dialog box.<\/li>\n\n\n\n
- Under When starting Microsoft Outlook, use this profile<\/strong>, select Prompt for a profile to be used<\/strong>, and then click OK<\/strong>.<\/li>\n\n\n\n
- Restart Outlook. In the Choose Profile<\/strong> dialog box, click on the dropdown list to choose the new profile. Click OK<\/strong>.<\/li>\n<\/ul>
Method 5 – Verify Outlook Account Settings<\/h3>
The Outlook error 0x80049dd3 may occur if Outlook fails to connect to mail server due to incorrect server settings. Make sure the POP\/IMAP port numbers are correct and the option “requires login using Secure Password Authentication (SPA)” is selected. In case there are any changes, you must update them. The steps are as follows:<\/p>
\n- Open Outlook.<\/li>\n\n\n\n
- Go to File > Info > Account Settings<\/strong>.<\/li>\n\n\n\n
- Select Account Settings<\/strong> from the dropdown and then under the Email<\/strong> tab, select your email account.<\/li>\n\n\n\n
- Click Change.<\/strong><\/li>\n\n\n\n
- Then, under the Outgoing mail server (SMTP), check the server address and port settings.<\/li>\n\n\n\n
- Ensure that My outgoing server (SMTP) requires authentication or Requires login using Secure Password Authentication (SPA) is checked. This is located under the More Settings tab.<\/li>\n<\/ul>
![\"POP](\"https:\/\/www.stellarinfo.com\/blog\/wp-content\/uploads\/2025\/08\/POP-Account-setting.png\")
<\/figure>\n- Once all the details are updated, save the changes and restart Outlook.<\/li>\n<\/ul>
Now, try sending an email to see if the error is resolved.<\/p>
Method 6 – Start Outlook in Safe Mode and Disable the Add-ins<\/h3>
Faulty or incompatible third-party add-ins may cause various issues in Outlook. You can run Outlook in Safe Mode to identify if any faulty add-in is causing the 0x80049dd3 error. To open Outlook in safe mode,<\/p>
\n- Press Windows + R<\/strong> to open the Run dialog box.<\/li>\n\n\n\n
- Type Outlook \/safe and press Enter <\/strong>or click OK<\/strong>.<\/li>\n<\/ul>
![\"Use](\"https:\/\/www.stellarinfo.com\/blog\/wp-content\/uploads\/2025\/08\/Run-command.png\")
<\/figure>If the Outlook application opens without the error in Safe Mode, then it is clear that a faulty add-in was causing the error. So, follow these steps to disable the add-ins:<\/p>
\n- Go to File<\/strong> > Options<\/strong> > Add-ins<\/strong>.<\/li>\n<\/ul>
![\"Go](\"https:\/\/www.stellarinfo.com\/blog\/wp-content\/uploads\/2025\/08\/outlook-options.png\")
<\/figure>\n- Under View and manage Office add-ins<\/strong>, select COM Add-ins<\/strong> from the Manage<\/strong> dropdown and then click Go.<\/strong><\/li>\n\n\n\n
- Uncheck all the add-ins and click OK.<\/strong><\/li>\n<\/ul>
![\"Uncheck](\"https:\/\/www.stellarinfo.com\/blog\/wp-content\/uploads\/2025\/08\/COM-add-ins-1.png\")
<\/figure>\n- Click File > Exit <\/strong>to close Outlook.<\/li>\n\n\n\n
- Now, start Outlook normally.<\/li>\n<\/ul>
To find the faulty add-in, you can go to the COM add-ins window and enable one add-in at a time. Restart Outlook after enabling every add-in. When you found the problematic add-in, remove it permanently from Outlook.<\/p>
Method 7 – Repair Corrupt PST File<\/h3>
In Outlook, all the mailbox data on the local storage is stored in a Personal Storage Table (PST) file. If this file is corrupted or damaged, you may fail to access the mailbox items. In such a case, you can run the Inbox Repair Tool (Scanpst.exe)<\/a> to scan and repair the corrupt PST file. But the ScanPST\/Inbox repair tool can help fix only minor corruption issues in the PST file. Also, it may not repair a large, highly corrupted PST file.<\/p>
There are some other reasons that may also cause this error, such as:<\/p>
- \n
- Incorrect Outlook configuration<\/li>\n\n\n\n
- Conflicts with add-ins or external programs<\/li>\n\n\n\n
- Unregistered or missing DLL files<\/li>\n\n\n\n
- Corrupt or incomplete Office installation<\/li>\n\n\n\n
- Corruption in Outlook data file (PST)<\/a><\/li>\n<\/ul>
Troubleshooting Methods to Resolve Outlook Error 0x80049dd3<\/strong><\/h2>
When you get the sign-in error prompt, do not click on continue to sign-in. As a way around, close the sign-in prompt by clicking on the close (X<\/strong>) button, instead of continuing. This helps you to access emails in Outlook but it is not a permanent solution. To resolve the error, you can try the below-mentioned troubleshooting methods.<\/p>
Method 1 – Repair or Reinstall Outlook (MS Office)<\/h3>
The error 0x80049dd3 may occur if the Outlook program files are damaged or corrupted. In such a case, you can try repairing or reinstalling the Outlook (MS Office) program. To repair the program, follow these steps:<\/strong><\/p>
- \n
- Open the Control Panel and go to Programs > Programs & Features > Uninstall a program<\/strong>.<\/li>\n\n\n\n
- From the list of programs, choose Microsoft Office<\/strong> and click Change<\/strong>.<\/li>\n\n\n\n
- Continue to follow the onscreen prompts to repair Microsoft Office and Outlook.<\/li>\n<\/ul>
If repairing the program didn’t fix the error, you can uninstall MS Office and do a fresh install.<\/p>
Method 2 – Clear Cached Credentials<\/h3>
Outdated or corrupted login tokens\/credentials stored in your system can cause authentication issues in Outlook. In such a case, you can try clearing the cached credentials. To remove the saved credentials, follow these steps:<\/p>
- \n
- Open Control Panel<\/strong>, click User Accounts<\/strong>, and then click Credential Manager.<\/strong><\/li>\n<\/ul><\/figure>
- \n
- In the Credential Managers window, go to Windows Credentials and look for entries related to Outlook <\/strong>and<\/strong> MS Office<\/strong>.<\/li>\n\n\n\n
- Click on the required entry to expand it and then click Remove from Vault <\/strong>or <\/strong>Remove<\/strong>, depending on the Windows version you’re using<\/strong>.<\/li>\n\n\n\n
- After removing the stored credentials, restart Outlook and then try to sign in again when prompted.<\/li>\n<\/ul>
Method 3 – Re-register the DLL File in Windows<\/h3>
Outlook application relies on the Windows DLL file (inetcomm.dll) to perform tasks, like sending\/receiving emails or syncing with servers. If this file is deleted or missing, it can lead to errors when accessing emails. To resolve the issue, you can re-register the inetcomm.dll file in Windows. For this,<\/p>
- \n
- Open the Run<\/strong> dialog box (click ‘Windows’ + ‘R’ keys together).<\/li>\n\n\n\n
- Next, type regsvr32 inetcomm.dll.<\/li>\n<\/ul>
Method 4 – Create a New Outlook Profile<\/h3>
The Outlook profile contains all the information related to Outlook configuration, email accounts, data files, etc. If the profile gets corrupted or damaged, you may face issues when logging in or accessing the emails or other items in Outlook. If your Outlook profile is corrupted, you can create a new profile<\/a> and replace it with the corrupted one. To do so, follow these steps:<\/p>
- \n
- Open the Control Panel on your system. Click User Accounts<\/strong> and then click Mail<\/strong>.<\/li>\n<\/ul><\/figure>
- \n
- In the Mail Setup-Outlook<\/strong> window, select Show Profiles<\/strong> and then click Add<\/strong>.<\/li>\n\n\n\n
- In the Profile Name<\/strong> field, enter the name you want to use for your new profile.<\/li>\n\n\n\n
- On the Auto Account Setup<\/strong> window, under E-mail Account<\/strong>, enter Your Name<\/strong>, E-mail Address<\/strong>, and Password<\/strong>, and then click Next<\/strong> > Finish<\/strong>.<\/li>\n\n\n\n
- You can check the new profile under the General<\/strong> tab in the Mail<\/strong> dialog box.<\/li>\n\n\n\n
- Under When starting Microsoft Outlook, use this profile<\/strong>, select Prompt for a profile to be used<\/strong>, and then click OK<\/strong>.<\/li>\n\n\n\n
- Restart Outlook. In the Choose Profile<\/strong> dialog box, click on the dropdown list to choose the new profile. Click OK<\/strong>.<\/li>\n<\/ul>
Method 5 – Verify Outlook Account Settings<\/h3>
The Outlook error 0x80049dd3 may occur if Outlook fails to connect to mail server due to incorrect server settings. Make sure the POP\/IMAP port numbers are correct and the option “requires login using Secure Password Authentication (SPA)” is selected. In case there are any changes, you must update them. The steps are as follows:<\/p>
- \n
- Open Outlook.<\/li>\n\n\n\n
- Go to File > Info > Account Settings<\/strong>.<\/li>\n\n\n\n
- Select Account Settings<\/strong> from the dropdown and then under the Email<\/strong> tab, select your email account.<\/li>\n\n\n\n
- Click Change.<\/strong><\/li>\n\n\n\n
- Then, under the Outgoing mail server (SMTP), check the server address and port settings.<\/li>\n\n\n\n
- Ensure that My outgoing server (SMTP) requires authentication or Requires login using Secure Password Authentication (SPA) is checked. This is located under the More Settings tab.<\/li>\n<\/ul>
<\/figure>- \n
- Once all the details are updated, save the changes and restart Outlook.<\/li>\n<\/ul>
Now, try sending an email to see if the error is resolved.<\/p>
Method 6 – Start Outlook in Safe Mode and Disable the Add-ins<\/h3>
Faulty or incompatible third-party add-ins may cause various issues in Outlook. You can run Outlook in Safe Mode to identify if any faulty add-in is causing the 0x80049dd3 error. To open Outlook in safe mode,<\/p>
- \n
- Press Windows + R<\/strong> to open the Run dialog box.<\/li>\n\n\n\n
- Type Outlook \/safe and press Enter <\/strong>or click OK<\/strong>.<\/li>\n<\/ul>
<\/figure>If the Outlook application opens without the error in Safe Mode, then it is clear that a faulty add-in was causing the error. So, follow these steps to disable the add-ins:<\/p>
- \n
- Go to File<\/strong> > Options<\/strong> > Add-ins<\/strong>.<\/li>\n<\/ul><\/figure>
- \n
- Under View and manage Office add-ins<\/strong>, select COM Add-ins<\/strong> from the Manage<\/strong> dropdown and then click Go.<\/strong><\/li>\n\n\n\n
- Uncheck all the add-ins and click OK.<\/strong><\/li>\n<\/ul>
<\/figure>- \n
- Click File > Exit <\/strong>to close Outlook.<\/li>\n\n\n\n
- Now, start Outlook normally.<\/li>\n<\/ul>
To find the faulty add-in, you can go to the COM add-ins window and enable one add-in at a time. Restart Outlook after enabling every add-in. When you found the problematic add-in, remove it permanently from Outlook.<\/p>
Method 7 – Repair Corrupt PST File<\/h3>
In Outlook, all the mailbox data on the local storage is stored in a Personal Storage Table (PST) file. If this file is corrupted or damaged, you may fail to access the mailbox items. In such a case, you can run the Inbox Repair Tool (Scanpst.exe)<\/a> to scan and repair the corrupt PST file. But the ScanPST\/Inbox repair tool can help fix only minor corruption issues in the PST file. Also, it may not repair a large, highly corrupted PST file.<\/p>
- Now, start Outlook normally.<\/li>\n<\/ul>
- Uncheck all the add-ins and click OK.<\/strong><\/li>\n<\/ul>
- Under View and manage Office add-ins<\/strong>, select COM Add-ins<\/strong> from the Manage<\/strong> dropdown and then click Go.<\/strong><\/li>\n\n\n\n
- Type Outlook \/safe and press Enter <\/strong>or click OK<\/strong>.<\/li>\n<\/ul>
- Press Windows + R<\/strong> to open the Run dialog box.<\/li>\n\n\n\n
- Select Account Settings<\/strong> from the dropdown and then under the Email<\/strong> tab, select your email account.<\/li>\n\n\n\n
- In the Profile Name<\/strong> field, enter the name you want to use for your new profile.<\/li>\n\n\n\n
- In the Mail Setup-Outlook<\/strong> window, select Show Profiles<\/strong> and then click Add<\/strong>.<\/li>\n\n\n\n
- Next, type regsvr32 inetcomm.dll.<\/li>\n<\/ul>
- Click on the required entry to expand it and then click Remove from Vault <\/strong>or <\/strong>Remove<\/strong>, depending on the Windows version you’re using<\/strong>.<\/li>\n\n\n\n
- In the Credential Managers window, go to Windows Credentials and look for entries related to Outlook <\/strong>and<\/strong> MS Office<\/strong>.<\/li>\n\n\n\n
- From the list of programs, choose Microsoft Office<\/strong> and click Change<\/strong>.<\/li>\n\n\n\n
- Open the Control Panel and go to Programs > Programs & Features > Uninstall a program<\/strong>.<\/li>\n\n\n\n