Vic's suggestion appeared while I was composing this. It sounds good (better than mine!) but I'll post anyway....
I know nothing about emclient, or about modern versions of windows. But as a general consideration, how long are you waiting before 'giving up' on the revolving arrow?
One thought is ghat might be trying to download a single very large item, such as an email with multiple photo attachments. In that case, depending on your broadband speed, it could take upwards of a minute to tens of minutes. After that large item is downloaded, normal responsivemess would resume.
Some clients perform housekeeping tasks from time to time, reorganising their databases and maybe compressing archived mail. That can also take a while, depending on cpu and disk speed, maybe a minute or so even up to tens of minutes.
In summary, I'd leave it to its own devices, spinning arrow, for at least an hour before giving up.