Why are My Emails Going to Outbox and Not Sending

The most error by most of the users is emails getting stuck in Outbox error. The same is a prevalent issue for professionals who are almost daily working and engaging in their businesses through Outlook. Most of the time, the process becomes too complicated and prolonged that it gets trapped in Outbox or drafts folders.

There are cases when users are getting the sent emails in sent folders, too, but they are not sent. Also, there may be incorrect server, firewall, or anti-virus configuration settings, which may be halting emails from sending. Let us first discuss the causes and then the solutions for the error.

Causes of the Error

Numerous solutions for the same error exist, but let us first have a quick look at the causes of the same. 

Large Attachments

The first and the foremost possible cause of the same is when you attach too many attachments with the email. There is always a quota limit where you can attach specific bandwidth of attachments; therefore, you need to check this first. Also, you can have a look at the size of attachments, i.e., if you are attaching images, they must be reduced to a smaller size or can be compressed to send the email smoothly.

If the email attachment is too large, check out other ways to transfer big files. Sometimes, attachments are of standard size but are more in number, hence, making sending slower.


Email marked as Viewed

Sometimes, users install add-ins, which mark their emails are viewed in Outbox, signaling the platform that email has been sent already. In that case, email is not sent but shows as sent. The same sometimes gets stuck in Outbox too and even after numerous restarts, is not sent 

The Outlook is not authenticated

Another reason for the same error is the no or wrong authentication of the Outlook server. Proper mail server is not set, and incoming or outgoing server settings are incorrect. Sometimes, the port is also wrong. You can check any of the said settings for the mentioned error.

The Outlook is already in use

It can be possible that Outlook is in use by any other user or program, making settings halt. You can check if the server is frozen or email is jammed in Outbox.

Anti-Virus is Restricting Outlook

Anti-virus sometimes is configured in a wrong way, and it may be possible that the settings are not correct. Maybe, there are inclusions or exclusions added for added security or scanning. You can check the same and can act accordingly. 

Office Registration

This can happen many times when your office application is not updated and registered. This leaves you with many errors, and you can’t even work on any Office application, not just Outlook. Just check if the suite is registered and properly activated. 


After you are well aware of the error and issues faced, you can then resolve them amicably and efficiently. Let us discuss the methods.

Outlook Connection Status

You can check Outlook connection, i.e., mail server settings or state. You can check if the server is offline or online. If the server is offline, the email messages will not be sent and will remain in the Outbox. They will remain there in Outbox until server state changes to online. You can change server status by the following steps.

  • At the top right of Outlook, check if “Connected” is written. If yes, the problem does not relate to the server state
  • If the answer to the previous step is No, i.e., working offline, you should now go to the Send/Receive tab and click the Work offline tab. Now, try sending email again
  • If the status is disconnected, check your internet connection

Resend Email

This may not always work, but if you feel all settings are correct, you should keep sending emails repeatedly. If the same leaves the Outbox immediately, consider your problem as solved.  

PST Backup 

You can take PST file backup and then can re-install the Outlook if possible. Sometimes, an application re-install also fixes the issue. After installing, you have to create a new email account and then drop the PST file in the exact mail folder. The installation of Outlook is straightforward. You need to take Microsoft office CD/DVD and run the setup. From the setup, choose customized applications and then install Microsoft Outlook. There is no need to install Microsoft Office completely. 

OST Conversion Tool

This is the one method apart from the above-mentioned ones. This includes the inbox repair method. In this method, Outlook saves all contacts, emails, and settings in the OST file. You can do OST to PST conversion. The method is automated and works efficiently. It resolves all damages in the OST file and manages all corruption. It also works for large OST files and splits them as per user requirements. 

Summing it all up, the solutions we have discussed are the most common ones, and all of them are manual methods except the last one. The last one is a software tool, which is a paid tool in most of the cases. There are some limited versions available too for the necessary tasks, but for full features, you need to buy them. Hopefully, the solutions other than the last one will work in most of the cases.

Also, few other manual solutions may include password resetting, outlook re-installing, server reset, taking PST backup, scanning PST files manually, and much more. It all depends on the issue you are facing, and the solution may be adopted appropriately.   

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