Your screenshot is all black. However, to the right of the list of smtp servers is a 'remove' button. Highlight the server to remove and click the button. To set a default, highlight an account in the accountsettings panel, click the 'account actions' drop-down menu and click 'default'. The smtp server that is identified on server settings panel for that account will be the default smtp server.

Thank you David.

First, the screen shot should not be all black. I blacked out account servers that I do not want made public. Please look again.

Second, please refer to the screen shot and see that there is no 'remove' button shown to the right of the list of SMTP servers. I re-visited the Outgoing Server (SMTP) down arrow at least another half dozen times and there is no visible 'remove' button.

Third, I did as you instructed to Set Default. That seems to have worked. Thanks!

I'm pleased the default setting worked. On the screenshot you submitted, I don't know where you got that. I am attaching a sample of what that panel looks like. It is on the accountsetting page.

The image you submitted appears to be from the Manage Identities button.

In the Outgoing Server (SMTP) line is a box with a little down arrow to the right. When I select that little down arrow, a window of SMTP servers appears. That is the screen shot I submitted.

When I click on Manage Identities button, there is only one server, the default server, in the window. When I highlight each account, then click the Manage Identities button, ONLY that account's SMTP server is shown.

Ah,ha! The Outgoing Server (SMTP) selection appears in TWO DIFFERENT PLACES! One at the bottom right of the highlighted account settings, and one at the extreme bottom of the Identities pane on the left of the Account Settings window is Outgoing Server (SMTP). The one at the extreme bottom of the Identities panel has the 'remove' button you referred to! Very confusing, Thunderbird! Put two action options in different places, don't tell the user, give one options and don't give the second one the same! Yeah, thank a lot, Thunderbird.

And thank you David for your patience. I hope others read this post and make note of which of these two action options to choose. Maybe you could write a pinned comment to address this for future reference by others.

Additional screen shot

It's a matter of what the purpose is. The one I use is for managing the smtp servers. The one in Managing Identities is primarily to allow selecting the server for an identity. Anyway, I hope all is well. If so, please mark this solved, so it will be removed from open issues list. Thanks.

Of course. The issue for me is that the managing smtp server option in the left panel is/was not visible due to the number of accounts listed, therefore I did not know it was there. Nor did I find any thing to direct me to that location to manage the servers. The only option I found was the one in managing identities. But all is well, the issue is resolved