How do I send an email from a shared mailbox?

• Open Outlook
• Click New Email
• Click the From dropdown and choose the email address you want to send from
• If it is not there already, select Other Email Address...
  
• Type the email address of your shared mailbox and click OK

If you cannot see the From dropdown:

• In a new message click the Options tab
• In the Show Fields section, make sure From is selected