Cannot send emails in classic outlook

Since receiving works but sending fails only for the Virgin Media account, focus on the outgoing server path for that account.

1. Check whether classic Outlook is offline.
   • At the bottom of the Outlook window, look for Disconnected, Working Offline, or Trying to connect….
   • If Working Offline appears, go to Send/Receive on the ribbon and select Work Offline to switch back online.
2. Confirm internet connectivity.
   • Open a browser and verify that common sites load.
   • If the connection is unstable, Outlook may receive intermittently but fail SMTP authentication or send operations.
3. Re-enter the password for that account.
   • If the password was changed on the provider’s website, it must also be updated in classic Outlook.
   • For third-party providers, the password change must be done with the provider first, then updated in Outlook.
4. Check whether the provider requires a special app password.
   • If Outlook shows a message like Please create an app password for Outlook on your email provider's site, get the app password from the email provider and use that in Outlook instead of the normal password.
5. Verify the outgoing account settings against the provider’s current SMTP settings.
   • The SMTP logon error indicates the outgoing server settings or credentials for the Virgin Media account may not match what the provider expects.
   • In classic Outlook, compare the account settings with the provider’s published POP/IMAP/SMTP settings.
6. If account repair did not help, reconfigure the Virgin Media account.
   • Remove and add that account again using the provider’s correct settings.
   • This is especially useful when only one account in the same Outlook profile fails while another account works.
7. Start classic Outlook in safe mode to rule out add-ins.
   • Press the Windows key, type outlook.exe /safe, and press Enter.
   • If sending works in safe mode, an add-in may be blocking send operations. Creating a new Outlook profile is the next step.
8. Repair the Outlook profile.
   • If the issue continues only in classic Outlook, repair the profile or create a new one.
9. Check antivirus email scanning.
   • Some antivirus products scan outgoing mail and can block sending if they detect a problem.
10. If messages are stuck in Outbox, inspect them.

• Large attachments can block sending. Open the Outbox, start with the oldest message, and remove attachments larger than 20 MB.

A practical order for this case:

• Re-enter the Virgin Media password
• Check whether Virgin Media requires an app password
• Verify the Virgin Media SMTP settings
• Re-add only the Virgin Media account
• Test in outlook.exe /safe
• Repair or recreate the Outlook profile

References:

• I can't send or receive messages in Outlook
• Troubleshoot Outlook email setup