Turn off junk mail controls in Tools/Account Settings/accountname/Junk Settings, and then under the Synchronization & Storage section for the account, click Advanced... and check the Junk/Spam entry to have TB download that folder. This of course only applies to IMAP accounts, as POP accounts only download the Inbox.

First, I am not even sure whether my account is IMAP or POP.

To get to Account Settings I use Edit rather than Tools. Under Junk Settings I remove the tick on

'Enable adaptive junk mail controls on this account'.

Immediately under 'Junk Settings' is Synchronization & Storage.

I click on that and then 'Advanced'.

That shows my email address and a click on that shows a list of my folders but NOT 'Junk'. ( However there is a 'Bulk Mail' folder, whatever that is.

Certainly not visible in  the webmail version of my account. )

So it looks like my account is POP. The only reason I look in Spam at all is that every now and then a valid email ends up there.

Under Server Settings in Account Settings it states Server Type.

"Junk" is the term used by TB; your mail provider may use Junk, Spam, or Bulk Items or Mail. Whatever it is, right-click the account in the Folder Pane, Subscribe, Refresh, and check the folders that you wish to download (assuming it's IMAP).

Thanks, that worked. Must admit though I was a bit confused. I realise that different email systems have different names for Spam. But, first, I thought, as you said yourself, that 'Junk' was the term used by TB. However in TB I still see no 'Junk' folder. And when I went to change

Advanced settings,as you advised, I was confused to see 'Bulk'.

( It is one thing for TB to call it that itself but another thing for it to say that that is what some other system calls it. )

Anyway, case closed and thanks again.