How do I reply or send an email from a shared mailbox address, rather than my own email address?
Outlook (Desktop Version)
Open a new email
Go to Options tab > show Fields and select "from" to add that field to all new emails
From here, you can change the send address by clicking on the from field
Outlook (Online)
Go to Settings (top right near profile name)
Go to 'View all outlook settings' (right at the bottom of the menu)
Go to 'Compose and reply'
Scroll down to 'Message Format' and tick the box 'Always show from'
Hit Save.
You can then change the address, by hitting the from field;