In December Citrix ShareFile added “soft” storage quotas into the product. By “soft” I mean that if you exceed the quota you aren’t prohibited from uploading more data, you are just annoyed by messages such as the one you see below and nag emails.
You will also see an indicator of your storage used vs the quota configured at the bottom of the webUI when looking at the My Files & Folders tab.
To set the quota login to your ShareFile account at https://%accountname%.sharefile.com and select Admin > Advanced Preferences
There you will see the configuration option for Storage Quota
You can also set or change the quota for individual users. To do this navigate to Manage Users > Search for Employee and then select the employee to edit by clicking on the pencil icon
Under the section Basic Information you will see an entry for User Storage Quota where you can select the company default quota or a custom quota.
Release notes for this specific release http://discussions.citrix.com/topic/345951-sharefile-release-notes-14-december-2013/
Follow the release notes for ShareFile releases here http://discussions.citrix.com/forum/1372-release-notes/