Emails need to be re-loaded?

Help please!
I am new to em client after transferring emails from mac mail. Not sure if I need to change settings but my emails disappear after closing em client and re-opening. All my subfolders show “There are no messages to show in this view” and I have to click “Load more” to see any of my emails. After they are downloaded again some will show as unread, sometimes all of them. My inbox only shows emails from the current day unless I click load more. This is making things really difficult!
Any help would be appreciated, thank you!
My ISP is Skymesh
My email is a Bigpond account
Em client version 9.0.1317

Please go to your menu bar and choose Accounts, then click on the IMAP tab for the account.

Scroll down to Sync Options and change the sync time period to All Time.

Click on Save & Close.