How to Fix Delivery Incomplete Gmail Error on Windows 11: Step-by-Step Solutions

If you are experiencing the “Delivery Incomplete” error when trying to send emails from Gmail on your Windows 11 device, it can be frustrating. This error usually means that your email was not successfully sent, and you need to fix it to resume smooth communication.

This guide will walk you through simple and effective steps to resolve the Gmail delivery incomplete issue on Windows 11. Each step is explained in a clear and basic manner, so even beginners can follow along easily.

By following these solutions, you will understand what causes the problem and how to troubleshoot it efficiently. Let’s get started and fix your Gmail sending issues.

The solutions listed below are arranged from the easiest to more advanced, helping you avoid unnecessary complications.

Quick Note Before You Begin

Make sure your internet connection is stable. A weak or disconnected network can cause sending errors.
Confirm you are logged into the correct Gmail account on your browser or mail client.
Check if Gmail’s servers are up and running by visiting Google Workspace Status Dashboard.
Ensure your Windows 11 system and browser are updated to the latest versions.

Step 1: Refresh Your Browser and Gmail

Sometimes, the simplest fix is to reload the Gmail page. If your browser has been open for a long time, some temporary glitches can cause errors.

Click the refresh button in your browser or press F5 on your keyboard.
Try logging out and logging back into your Gmail account.
Close the browser completely and reopen it, then try sending the email again.

This step helps clear temporary browser glitches and refreshes your session with Gmail’s servers.

Step 2: Check Your Email Recipients and Attachments

The “Delivery Incomplete” error can be caused by incorrect email addresses or problematic attachments.

Verify that all recipient email addresses are correctly typed without extra spaces or missing characters.
If you included attachments, make sure the files are not too large or corrupted.
Try sending a simple text email without attachments to test if the problem persists.

Incorrect addresses or large attachments often cause Gmail to fail sending your message.

Step 3: Clear Browser Cache and Cookies

Cached data and cookies may sometimes interfere with Gmail’s performance, causing errors.

Open your browser’s settings menu.
Find the section for clearing browsing data (usually under Privacy or History).
Select options to clear cached images and files, and cookies for the last 24 hours or all time.
Restart your browser and sign in to Gmail again.

This step removes old or corrupted data that might be interrupting Gmail’s functionality.

Step 4: Disable Browser Extensions

Some browser extensions can conflict with Gmail and cause sending errors.

Access your browser’s extensions or add-ons menu.
Temporarily disable all extensions.
Reload Gmail and try sending your email again.
If it works, enable extensions one by one to find the problematic one.

Extensions that modify web pages or email content can sometimes block or alter Gmail’s processes.

Step 5: Use Gmail in a Different Browser or Incognito Mode

Trying Gmail in another browser or incognito/private mode can help identify if the problem is browser-specific.

Open an incognito window by pressing Ctrl + Shift + N in Chrome or Ctrl + Shift + P in Firefox.
Log into your Gmail account and try sending the email.
If it works, the problem likely lies with your default browser’s settings or extensions.
You can also try using a different browser like Edge, Firefox, or Chrome to test.

Step 6: Check Your Email Client Settings (If Using a Desktop App)

If you use a mail client like Outlook or the Windows Mail app to send Gmail, incorrect settings may cause delivery failures.

Confirm the SMTP server is set to smtp.gmail.com with port 465 or 587.
Make sure SSL or TLS encryption is enabled.
Verify your username and password are entered correctly.
Check if you have allowed access for less secure apps in your Google Account settings or generated an app-specific password if 2-Step Verification is enabled.

Proper email client configuration is essential for successful email sending through Gmail.

Step 7: Review Google Account Security Settings

Google may block sending emails if it detects suspicious activity or security risks.

Go to your Google Account Security page.
Check for any recent security alerts and follow prompts to secure your account.
Enable 2-Step Verification if not already done to increase account security.
Allow access to less secure apps if necessary, but be cautious as this lowers security.

Updating your account’s security settings can prevent Gmail from blocking your outgoing messages.

Step 8: Temporarily Disable Firewall or Antivirus Software

Sometimes, firewall or antivirus programs on Windows 11 might block Gmail’s sending functions.

Open your antivirus or firewall software settings.
Temporarily disable real-time protection or firewall features.
Try sending the email again.
If it works after disabling, add Gmail or your mail client to the exception list in the security program.

Be sure to enable your protection software again after testing to keep your system safe.

FAQs

Why do I get the “Delivery Incomplete” error in Gmail?

This error usually occurs when Gmail cannot send your email due to invalid addresses, server issues, connectivity problems, or incorrect client settings.

Can a slow internet connection cause this error?

Yes, a poor or intermittent internet connection can interrupt the email sending process and result in delivery errors.

Is it safe to allow less secure apps access in Google Account?

Allowing less secure apps reduces your account’s security and is not recommended unless absolutely necessary. Using app-specific passwords with 2-Step Verification is safer.

Will clearing cache delete my saved emails?

No, clearing your browser cache and cookies will not delete your emails. It only removes temporary files stored by the browser.

What if I use Gmail through a third-party mail client?

You need to ensure your mail client is correctly configured with Gmail’s SMTP settings and your account permissions are set properly.

When Nothing Works

If you have tried all the above steps and still face the “Delivery Incomplete” error, consider the following options:

Visit the official Google Mail Help Center for more assistance.
Check Google’s Workspace Status to confirm there are no ongoing Gmail outages.
Contact your internet service provider to check for network issues.
Try using a different device to see if the problem is specific to your Windows 11 computer.
As a last resort, create a new Gmail account and test sending emails from there.

Conclusion

The “Delivery Incomplete” Gmail error on Windows 11 can be caused by many simple issues such as browser glitches, incorrect recipient addresses, or security settings. By following the step-by-step solutions above, you can troubleshoot and resolve the problem efficiently.

Start with basic fixes like refreshing your browser and checking email details, then move on to clearing cache, testing different browsers, and verifying account security. If you use an email client, ensure its settings are correct.

Remember to keep your system and apps updated, and maintain a stable internet connection for the best Gmail experience. With patience and these clear instructions, you can get your emails delivered without trouble once again.