I recently posted a request for help in this forum under the title 'Accounts: auto-setup yields wrong details'. I received no replies, unfortunately. Since then I have discovered a couple of things that make it worth my posting again under a new title.

I have MS Office 2016 for Mac on my Mac mini with MacOS 10.12.2 (Sierra). I have a gmail and a btinternet email account. (Also an icloud one, but I am not concerned with that here.)

I encountered no difficulties when setting up my gmail account in Outlook, and it works perfectly well. But I cannot get Outlook to send or receive mail in my btinternet account. I first tried the automatic set-up. This insisted that my account is a POP one, but in fact it is an IMAP one, so I tried again with manual set-up. In each case, Outlook refuses to send or receive btinternet mail. I experimented with enabling and disabling SSL, and confirmed that the right servers were shown, still with no success.

The BT internet service (linked to Yahoo!) is problematic, as anyone using it will know. But this present problem is also an Outlook problem, because I have not had any difficulties in setting up a properly-working btinternet mail account in Safari, either on my Mac or on my iPhone.

I should be most grateful for any help or advice.