Messages stuck in the Outbox point to a large attachment or an offline connection according to Microsoft. Switch off Work Offline first. Remove the attachment next and check the send immediately option. Repair the PST file when the message returns.
Email stuck in the Outlook Outbox folder is the problem where a sent message waits in the Outbox and never reaches the recipient. Outlook shows no clear error and you resend the message while the copies pile up.
This guide explains five fixes starting with the offline switch and ending with PST repair software.
Microsoft lists the fixes in its article on messages stuck in the Outbox.
Why do Messages Wait in the Outbox?
Microsoft names three causes for a stuck message:
- Large attachment. Microsoft's article calls a large attachment the most likely cause.
- Disconnected Send. Microsoft states a message waits in the Outbox when you press Send while disconnected.
- Send option disabled. Microsoft's Outlook email stuck article states the Send immediately when connected option causes this when it is disabled.
Microsoft documents no data file cause for the Outbox. Methods 4 and 5 test it.
Microsoft's steps for Outlook.com name 25MB as the attachment limit. Microsoft suggests a OneDrive link for larger files.
Which Outbox Sign do You See?
Match the sign to a method before you start:
| Outbox Sign | Check First | Method |
|---|---|---|
| Work Offline button is blue | Connection | Method #1 |
| Message has a large attachment | Attachment | Method #2 |
| Error says Outlook is trying to send the message | Task Manager | Method #2 |
| Mail waits for Send/Receive | Send option | Method #3 |
| Message returns after deletion | Data file repair | Method #4 |
| Repair finds no fix | PST repair software | Method #5 |
5 Ways to Fix Email Stuck in the Outlook Outbox Folder
Methods 1 to 4 cost nothing. Software handles Method 5:
| Fix Type | Documented By | Needs |
|---|---|---|
| Offline Switch | Microsoft article | Account connection |
| Attachment Removal | Microsoft article | Access to Drafts |
| Send Option | Microsoft article | Outlook 2010 or later |
| Inbox Repair Tool | Microsoft article | PST file |
| Software Export | Product page | Trial cap |
Method #1: Switch Off Work Offline and Press Send All (Free)
Microsoft links a stuck message to pressing Send while disconnected. Five steps send it:
- Open the Send/Receive tab.
- Check the Work Offline button because blue means you are disconnected.
- Select the button so it turns white.
- Press Send All.
- Open the Outbox and confirm the message is gone.
Note: Check your internet connection before you press Send All.
Method #2: Remove the Large Attachment From the Message (Free)
Microsoft's article calls a large attachment the most likely cause. Seven steps remove it:
- Select Send/Receive and then Work Offline.
- Open the Outbox in the Navigation Pane.
- Select the message and press Delete to remove it or drag it to Drafts.
- Double click the draft and select the attachment and press Delete.
- Close Outlook when an error says Outlook is trying to send the message.
- Open Task Manager with Ctrl + Alt + Delete if Outlook refuses to close and end outlook.exe on the Processes tab with End Process.
- Open Outlook again and repeat steps 2 to 4 before you switch Work Offline off.
Note: Microsoft lists the Task Manager step for the error that says Outlook is trying to send the message.
Method #3: Enable Send Immediately When Connected (Free)
Microsoft's Outlook email stuck article documents this option for Outlook 2010 and later. Five steps check it:
- Open File and select Options.
- Go to the Advanced category.
- Find the Send and receive section.
- Tick Send immediately when connected.
- Press OK.
Note: Microsoft states Group Policy manages the option when it is grayed out. Ask your administrator to remove the policy.
Method #4: Scan the PST File With the Inbox Repair Tool (Free)
Microsoft documents SCANPST for Outlook Data Files in the PST format. Six steps repair the file:
- Close Outlook and locate SCANPST.EXE in your Office folder.
- Open SCANPST.EXE and press Browse.
- Select your PST file and press Start.
- Press Repair when the scan reports errors.
- Edit the backup name or location in the backup box when needed.
- Open Outlook with the profile that uses the repaired file.
Note: Microsoft's repair article for Outlook data files gives the Office16 folder for Outlook 2016 and 2019. Microsoft's article also states the tool cannot analyze Exchange mailbox data and you can delete an offline OST file because Outlook recreates it.
Method #5: Export Mail From a Damaged PST File With EmailDoctor Outlook PST Repair Tool (Trial Limit Applies)
According to the product page EmailDoctor Outlook PST Repair Tool repairs corrupt PST files and OST files are not mentioned. Work on a copy so the original file remains safe.
Scan the Copy
Steps 1 to 3 add the file:
- Search Windows for the repair software and open it.
- Choose Add File from the toolbar.
- Select the PST copy in the file browser and confirm the scan mode with Add.
Export the Recovered Mail
Steps 4 to 6 finish the export:
- Open the Outbox folder in the list and look at the preview.
- Choose Export and select PST as the export type.
- Select a destination folder and confirm with Export.
Note: Product page separates the two stages. Scanning needs no Outlook while PST export uses the Use Outlook option and needs Outlook installed. Try one folder first since the free export caps at 25 items per folder.
What Does Your Outcome Mean?
Compare the result before the next method:
| Outcome | Indicates | Next Move |
|---|---|---|
| Outbox empties after Send All | Points to offline mode | Confirm Work Offline is white |
| Message sends without the attachment | Points to a large attachment | Share a smaller file |
| Mail sends after the option is ticked | Points to the send option | Confirm the box remains ticked |
| Message returns after deletion | Points to a data file problem | Method #4 |
| Repair finds no fix | Points to a damaged PST file | Method #5 |
Frequently Asked Questions
Why is Email Stuck in the Outlook Outbox Folder?
Microsoft names a large attachment as the most likely cause. Messages also wait there when you press Send while disconnected.
How do I Delete a Message From the Outbox?
Switch on Work Offline, open the Outbox and press Delete. Microsoft lists this step before the attachment fix.
What if the Work Offline Button is Blue?
Blue means you are disconnected according to Microsoft. Select the button so it turns white and press Send All.
Why is the Send Option Grayed Out?
Microsoft states Group Policy manages the option when it is grayed out. Ask your administrator to remove the policy.
Can SCANPST Fix Exchange Mailboxes?
No. Microsoft states the tool handles PST files only and cannot analyze Exchange mailbox data. Microsoft adds that you can delete an offline OST file and Outlook recreates it.
Is Outlook Required for the Scan?
No. Product page says the scan needs no Outlook but the PST export option needs it installed.
How Many Items Does the Free Version Export?
Product page lists a cap of 25 items for every folder.
Author’s Verdict
Start with the offline switch because a disconnected Send stalls the message. Remove the large attachment next.
Check the send option before you repair the PST file. Choose PST repair software when the message returns after every free step.
Create a backup of the PST file before you repair it.
- Select Work Offline until it is white and press Send All.
- Remove a large attachment through Drafts.
- Tick the send option.
- Repair the PST file with SCANPST.
- PST repair software exports mail from a damaged file.
Next Read: What to do When SCANPST Does Not Work
Also Read: Outlook Stuck at Processing | Outlook PST File Not Loading
