Only receiving the 1st "Welcome" message from Zoho when using IMAP with Thunderbird

Only receiving the 1st "Welcome" message from Zoho when using IMAP with Thunderbird

Hi,

I have created a basic (free) account. I have not changed my mx records (as I am only testing at this point), but I have successfully configured zoho to regularly retrieve email from my existing POP3 account.

If I log into Zoho with a web browser, all this email is visible in my inbox or spam folders, and appears to be correctly received.

However, if I connect to the account using Thunderbird, with an IMAP connection the only email I ever see is the original "Welcome" from zoho, which is shown in my inbox. Thunderbird does appear to see the other folders correctly, but there are no other emails in any of them.

Thanks in advance
  Steve