Sending and receiving takes more than 15 minute after sending each Gmail email

Question

I am running Outlook 2021 MSO (Version 2601 Build 16.0.19628.20204) 64-bit on an HP laptop running Windows 11 Version 25H2 (OS Build 26200.7840) and everytime I send a Gmail email message, Sending/Receiving runs for more than 15 minutes.

Here is a list of things I have tried without getting any improvement:

1. Confirmed my 1 Gig FiOS internet connection is stable and working properly.
2. Run Windows and Microsoft Update to make sure everything is up to date.
3. Incoming Mail
   1. Server: imap.gmail.com
   2. Port: 993
   3. Encryption: SSL/TLS
   4. SPA: unchecked
4. Outgoing Mail
   1. Server: smtp.gmail.com
   2. Port: 465
   3. Encryption: SSL/TLS
   4. Server Timeouts: 5 minutes
   5. SPA: Unchecked
   6. SMTP requires authentication: Checked; Use same settings as my incoming mail server
5. Eliminate AV and Firewall conflicts: I use Windows Security
6. The OST file is located at C:\Users\jim\AppData\Local\Microsoft\Outlook and is 14,822 MB. (I have not compacted it since it was created.)
7. This profile was created about 10 days ago and the long processing time started two days later.

Any help would be greatly appreciated.

Please provide details instructions.

Thanks!

Jim

Answer 1

Hello JWKinRVA,

Thank you for reaching out to the Microsoft Q&A forum. I sincerely appreciate you providing such detailed information regarding your Outlook and Windows versions; this is incredibly helpful for the diagnosis. 

Based on your description—specifically that your OST file has reached 14.8 GB in only 10 days—it appears that Outlook is attempting to index and synchronize every single item in your Gmail account, likely including the "All Mail" folder. This creates massive data redundancy and forces Outlook to re-scan every item during each Send/Receive cycle, leading to the 15-minute delays you are experiencing. 

To resolve this and optimize your performance, please follow these refined troubleshooting steps: 

1. Unsubscribe from Large Folders in Gmail 

• Log into your Gmail account via a web browser
• Select the Gear icon (Settings) > See all settings. 
• Navigate to the Labels tab. 
• Locate the folder labeled All Mail and uncheck the box for "Show in IMAP." 
• Restart Outlook to allow the changes to take effect. 

2. Manage the Data File and Sync Slider 

Since your current OST file is already quite large, I recommend creating a fresh, leaner profile to ensure a clean start. 

• Open the Control Panel: Search for and select Mail (Microsoft Outlook). 
• Create a New Profile: Click Show Profiles > Add, and name it "Outlook_New". 
• Add your Gmail Account: Follow the prompts to sign in via the Google/OAuth popup. 
• Limit the Sync Slider: This is a crucial step. When prompted (or via Account Settings), adjust the "Mail to keep offline" slider to 3 Months or 6 Months. 

Note: This keeps your local data file small and fast, while your older emails remain safely searchable on the Gmail website. 

3. Rebuild the OST File (If not creating a new profile) 

If you prefer to stay on your current profile, you should rebuild the data file after unsubscribing from the "All Mail" folder: 

• Press Windows Key + R, type %localappdata%\Microsoft\Outlook, and hit Enter. 
• Locate the large .ost file (approx. 14–15 GB) associated with your Gmail address. 
• Right-click and Rename it to youraddress.ost.old. 
• Re-open Outlook. The application will automatically generate a new, significantly smaller data file. 

4. Perform an Office Quick Repair 

If the synchronization still feels sluggish, there may be a minor glitch in the application files. 

• Navigate to Windows Settings > Apps > Installed Apps. 
• Find Microsoft Office 2021, click the three dots, and select Modify. 
• Choose Quick Repair and follow the prompts. 

Please try sending a test email after performing these steps. Should you continue to experience difficulties after completing these steps, please do not hesitate to reply to this thread. I am more than happy to provide further assistance. 

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Answer 2

If you're experiencing long delays in sending and receiving emails in Outlook, there are several potential causes and solutions to consider:

1. Check Outlook Settings: Ensure that the Send immediately when connected option is enabled in Outlook. This setting can be found under File > Options > Advanced > Send and receive. If this option is not enabled, your emails may stay in the Outbox until you manually initiate a send/receive operation.
2. Optimize Your OST File: Since your OST file is relatively large (14,822 MB), it may be beneficial to compact it. You can do this by going to File > Account Settings > Account Settings, selecting your account, and then clicking on Data Files. From there, you can select your OST file and choose to compact it.
3. Limit the Number of Items: If you have many items in your folders, especially in the Inbox, consider moving some emails to other folders or archiving them. Outlook can perform better with fewer items in the primary folders.
4. Check for Software Updates: Although you mentioned running updates, ensure that both Windows and Outlook are fully updated to the latest versions. Sometimes, specific updates address performance issues.
5. Run Microsoft Support and Recovery Assistant: This tool can help diagnose and fix issues with Outlook. It performs automated checks and can provide solutions to common problems.
6. Network Configuration: Since you have confirmed your internet connection is stable, ensure that there are no additional network configurations or restrictions that might be affecting Outlook's connectivity to Gmail servers.
7. Profile Issues: Since the issue started shortly after creating a new profile, consider recreating the profile again. Sometimes profiles can become corrupted, leading to performance issues.

If these steps do not resolve the issue, you might want to consider reaching out to Microsoft support for further assistance.

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References:

• Email stays in the Outbox folder until you manually initiate a send/receive operation in Outlook
• Fix Outlook connection problems for Microsoft 365 account