Whenever you send an email on Outlook, you expect it to be delivered instantly. However, like other email platforms, Outlook is prone to malfunctions and will sometimes fail to send your emails. If your outgoing emails fail to go through and you don’t know how to fix the issue, your communication will be disrupted and inefficient.
This article explains how to fix Outlook if it fails to deliver your emails.
7 Ways to Fix Outlook Not Sending Emails
Most of the time, when Outlook fails to send emails, the issue could be emanating from your device, the Outlook app, or Outlook servers. If the problem is from Outlook servers, there’s nothing much you can do but wait until Microsoft resolves it. However, if the issue comes from your device or the app, you can fix it without professional assistance.
1. Verify Your Outlook Is Online
Although Outlook allows you to work online and offline, some features have limited functionalities without an internet connection. For instance, your outgoing email might fail to be delivered if you send it in offline mode. Sometimes, you could be offline because you touched the offline mode accidentally. Other times, your device resets itself to offline mode when your internet connection is weak.
To verify, follow these steps:
- Launch your Outlook application and look at your connection status at the bottom.
- If it says “Connected,” you’re working in online mode, and your emails should go through.
- If it shows “Working offline,” this could be why Outlook is failing to send emails. You need to switch to online mode.
- To shift to online mode, hit the “Send/Receive” tab on the menu at the top.
- Navigate to the top right corner and tap “Work offline” to de-select the offline mode. Try resending the email to see if this resolves the issue.
2. Ensure Your Internet Connection Is Strong and Stable
A weak and unstable signal can cause Outlook not to send emails for several reasons. First, Outlook won’t be able to communicate with the email server, meaning data transmission will be delayed or disrupted.
Also, Outlook has an in-built feature that automatically times outgoing emails if they remain undelivered for a specific period. A poor connection will trigger a timeout error on your outgoing emails.
To rule out Internet connection as a cause of Outlook failing to send emails, run an internet speed test or switch to a different Wi-Fi network. Also, you can try connecting your device to the internet via an Ethernet cable. After ensuring your internet is working properly, return to your Outlook and try resending the emails.
3. Activate Transmission Control Protocol/ Internet Protocols (TCP/IP)
One of the networking protocol your device needs to facilitate data formatting, encryption, routing, and transmission is the Transmission Control Protocol (TCP) and Internet Protocol (IP) (TCP/IP). It enables smooth browsing, email communication, and file transfer.
If you haven’t activated TCP/IP, it could cause your outgoing Outlook emails not to be delivered. Here’s how to enable this protocol:
- Navigate to the bottom left of your screen and tap the “Windows” icon.
- Type “
ncpa.cpl” in the search bar and wait for it to load.
- Hit the “Open” button beneath it or the “Enter” button on your keyboard to go to the “Network connections” in the Control panel.
- Right-click the “Wi-Fi” option and select “Properties.” This will take you to the “Networking” page.
- Navigate to the “Internet protocol version 6 (TCP/IP) and check it.
- Click “OK” to save the changes. Return to your Outlook and try resending your emails.
4. Give Your Outlook a Repair
Outlook could develop glitches that make it impossible to carry out specific tasks. For example, if the Personal Folder Files where Outlook stores your data is corrupted, you may get an error message if you try to send an email. Also, ad-ins within the app could cause the app to malfunction.
In this case, the solution is repairing your Outlook using Microsoft Office’s repair tool as follows:
- Go to the search bar in the bottom left corner of your Window screen and type “
- Select the “Programs” option and click “Uninstall a program.”
- Choose “Microsoft 365” and tap “Change” at the top.
- A user account prompt pops up on the screen, asking you to confirm whether you want to make changes to the app. Tap “Yes,” to continue.
- On the next page, select “Quick repair” and tap “Repair” at the bottom of the screen.
- Go back to your Outlook and resend the email. If the problem persists, repeat the process, and instead of selecting quick repair, choose “Online repair.”
5. Restart Your Outlook App
Restarting Outlook can help refresh the app and clear all the issues preventing your emails from going through. For instance, it establishes new connections with email servers, clearing all connectivity issues. Also, it reinitializes ad-ins and resets cached data, allowing the app to perform optimally.
Here’s how to restart your Outlook app:
- Navigate to the Windows “Search bar” and type “Task manager.”
- Hit “Enter” when it appears on the search results.
- Select “Microsoft Outlook” from the app options and tap “End task.”
- Restart your Outlook again and see if your emails will be delivered.
6. Make a New Outlook Profile
Your profile can develop misconfigurations and corruption issues that could cause your Outlook features not to function normally. You can fix this problem by creating a new Outlook profile. However, beware that doing this creates a new slate that requires you to reconfigure the settings and reset the preferences.
Here’s how to create a new Outlook profile:
- Launch your Outlook app and tap the “File” option at the top.
- Select “Info” from the drop-down menu and tap “Account settings.”
- Choose “Manage profiles” and tap “Show profiles.”
- Hit the “Add” button towards the left to create a new profile.
- Type your “Profile’s name” and click “OK.”
- Enter your email on the open wizard.
- Tap the “Always use this profile” option and select your newly-created profile as your default.
- Tap “OK” to save the changes. Configure the profile’s settings and preferences as you wish.
- Restart your Outlook and check whether your email will be sent.
7. Check if Your Email’s Size Is within Outlook’s Specification
Like other email platforms, Outlook has email size restrictions for several reasons. First, its email servers don’t have an advanced capacity for processing files exceeding 20 MB. Second, transmitting data for large emails takes longer, causing delivery delays. Finally, it prevents spammers from flooding email servers with large emails.
If your email exceeds 20 MB, Outlook will fail to deliver it until you reduce the size. If you’ve attached multiple files in one email, you can try sending each individually to reduce the size. Also, you can send your file to cloud storage such as Dropbox, Google Drive, or OneDrive to get a link to your file. Instead of attaching the file to your email, you attach a link that the recipient will tap to view the file in your cloud storage.
Fix Outlook’s Outgoing Email Issues
As frustrating as it is when Outlook fails to send your emails, taking a strategic approach to fix the problem is the only way to get your communication back on track. Though it might be daunting to spot the exact problem, you can try applying any of the above fixes until your emails go through. If neither of the fixes works, contact Microsoft support for assistance.
When was the last time Outlook failed to send your emails? Did you use any of the methods featured in this article to fix the problem? Let us know in the comments section below.