Converting office365 exchange online mailbox to shared
  Converting office365 exchange online mailbox to shared   This can be done through EAC or Powershell     Using EAC     Log on to  Office365 portal  then navigate to Exchange Admin Center (EAC) or open  EAC  directly.  Select Admin tile to view your Admin center page.      Select Exchange from the Admin drop down.           Select mailboxes from the EAC page (or) Recipients > mailboxes       search and select the mailbox.   On the right hand pane, please click on convert to change the mailbox to shared      Using Powershell    Connect to Exchange online powershell  Enter any of the following command to convert the mailbox to shared.     Set-Mailbox -Identity "useralias@domain.com" -Type shared    Set-Mailbox "useralias@domain.com" -Type shared