Search Knowledge Base: What is my Office 365/Volmail email quota and what are the folder count recommendations? Email Quota Your Volmail/Office 365 mail quota is 50 GB. To check your quota: Log into Office 365 and choose the Mail app. Go to the upper right corner and select the Gear/Settings button. Under Your app settings choose Mail. On the left-hand side, select General > My account. Mailbox usage is on the My account page. Folder Count Recommendations Microsoft recommends keeping your top-level Inbox, Sent Items, Calendar, or Contacts/People folders (subfolders excluded) below the recommended item counts below. You may experience slow or sluggish performance if the item count exceeds Microsoft's recommendation. Inbox: 20,000 messages Sent Items: 20,000 messages Calendar: 5,000 items Contacts/People: 5,000 entries Need more help?