WorkMail not working

When setting up WorkMail over exchange in a Windows laptop running Outlook, I get the attached error below.

I Googled "error code 0x85010004 workmail" and found a related issue here: https://support.intermedia.com/app/articles/detail/a_id/10229//activesync-errors-on-windows-mobile-devices#::text=will%20be%20downloaded.-,ActiveSync%20error%200x85010004,not%20receive%20the%20error%20anymore.

SSL is enabled, email opens fine in an iPhone so all good with credentials and SMTP settings - what can be causing this error on a Windows laptop?

Thanks.