BT email with Outlook 2013 on Windows 11

[DavidBRose]

Having bought a new computer with Windows 11 and using Outlook 2013, emails are received with no problem, but always get an error when sending and receive an error message with the box to enter the password.  After that the screen keep requesting the password every few seconds and then I see a message saying the server rejected the login.

It's the same password whether sending or receiving, so why will it receive but not send?

The account is set up with IMAP

It works fine on another computer with a later version of Outlook.  In that case it's Outlook 2021, so I'm wondering if there might be a difference in the way Outlook 2013 communicates.  Everything else is identical.

I also tried changing the password and it's the same error.

I had a conversation with BT technical support and it was suggested that Norton might be interfering with it, so I turned off the option to scan outgoing emails, but that made no difference.

Any ideas will be welcome.

[licquorice]

Make sure you haven't ticked secure password authentication in the advanced outgoing section. The whole connection is secure and SPA is not required. You should be using port 465 with SSL selected.

[DavidBRose]

Thanks for your quick reply. SPA is not ticked.
I should have mentioned the settings used. They were automatically set when I added the account to Outlook 2013
Incoming 993 with SSL/TLS
Outgoing SMTP 465 with SSL/TLS
The outgoing tab says it requires authentication - same settings as incoming mail server is ticked

The settings are idential on the other computer using a later version of Outlook, so I'm wondering if that might be the issue

[licquorice]

The settings for all versions of Outlook are the same.

You could try deleting the account and setting it up again manually rather than letting Outlook do it automatically. Use your full email address as the username rather than just the first part before the @btinternet.com

[DavidBRose]

I deleted and added again manually and still it receives emails but still can't send. Settings are identical on both computers. One using Outlook 2013 and the other Outlook 2021.