After the Free trial expires, the data will be retained for 30 days and you will be able to access the data once you upgrade the account.
You can upgrade after login to the account:
Resume accounts
The email accounts will be paused automatically when the trial or plan expires.
Once you upgrade the plan, you will be able to access the dashboard and manually resume each account by following the steps below:
Click on email account
Click on the top-right Resume option