outlook, won't send messages through my gmail account.

Question

I have used my G-mail address <removed PII> though Outlook for several years and have not changed my settings. What happens is that mails sent from the <removed PII> address stay in the outbox. The progress bars take a long time to finish bu eventually do report 'completed - yet the mail remains in the outbox. Sending from Gmails web interface works fine. (My outlook account recently changed ID from <removed PII> to <removed PII>, but both addresses seem to work and all emails are received, so I do not think this is the cause of the problem which just arose today. 2nd July 2025)

Answer 1

Hi @Michael Prehn

Thank you for posting your question in the Microsoft Q&A forum. 
Please understand that our forum is a public platform, and we will modify your question to cover your email address in the description. Please notice to hide these personal or organization information next time you post error or some information to protect personal data.
I'm sorry to hear you're experiencing this issue. Since emails are sending fine through Gmail’s web interface, the issue likely lies with Outlook’s connection to Gmail’s SMTP server. 
Here are a few steps that may help resolve the issue:  

1.Open Outlook > File > Account Settings > Account Settings. 

2.Select the Gmail account > click on Change. 

3.Click on More Settings > Outgoing Server tab. 
If you do not see More Settings button, close Outlook completely > open Control Panel > search for and open Mail (Microsoft Outlook) > Click Email Accounts > Select your Gmail > Click on Change 

4.Check the box My outgoing server (SMTP) requires authentication >Use same settings as my incoming mail server  

5.Go to the Advanced tab > change the outgoing server (SMTP) port to 587 > OK.
  
If you've followed these steps and the problem continues, you might consider the following next steps to further troubleshoot the issue: 

1.Move out the email that is stuck on the Outbox: 

-Open Outlook > Send/Receive > Work Offline. 

-Move the email that got stuck Outbox folder to the Drafts folder. You can just drag and drop to move emails. 

-After moving the email, make sure to toggle back on the Work Offline and try resending the email again. 

2.Temporarily disable any third-party antivirus, firewall, or VPN software that might be interfering with Outlook’s connection to Gmail servers. 

I hope this helps. 

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Answer 2

Hi @Michael Prehn

Thank you for your update. 
You might want to try the following solution to address your problem: 

1.Enable IMAP in Gmail 

Go to https://mail.google.com/ 

Navigate to Settings > See all settings > Forwarding and POP/IMAP 

Ensure IMAP is enabled 

2.Use an App Password (if 2FA is enabled) 

Visit https://myaccount.google.com/apppasswords 

Generate a password for "Mail" and "Windows Computer" 

Use this app password in Outlook instead of your regular Gmail password 
You can refer to Sign in with App Passwords – Gmail Help 

3.Manually configure Outlook 

Key settings: 

-IMAP server: imap.gmail.com, Port: 993, SSL: Yes 

-SMTP server: smtp.gmail.com, Port: 587, TLS/STARTTLS: Yes 

-Authentication required for both incoming and outgoing servers 

You can refer to Choose your IMAP email client settings for Gmail 

4.Clear cached Credentials 

Open Control Panel > User Accounts > Credential Manager > Remove any stored credentials for Outlook or Gmail 

5.If Outlook still fails to connect: 

-Open Registry Editor 

-Navigate to:  *HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Common\Identity\Identities* 

-Delete the subkey related to your Gmail account 

-Restart Outlook and re-authenticate 

Note: Microsoft is providing this information as a convenience to you. The sites are not controlled by Microsoft. Microsoft cannot make any representations regarding the quality, safety, or suitability of any software or information found there. Please make sure that you completely understand the risk before retrieving any suggestions from the above link. 
I hope this works for you. 

Thank you for your patience and understanding. 

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