Sending "From" Another Email Address

Outlook Desktop:

• Open Outlook and start a new email.
• Click "Options" 
• Click "From"

• You will now see a drop down box to the left of your email address.
• Click "Other Email Address..."

• Enter the full email address of the email address you would like to send as.
• Click OK.
• Click the "From" box again and select the email you would like to send as.
• Compose your email and click Send.

Outlook Web App:

• Create a new email
• Click the three dots (...).
• Click "Show From"

• Click the blue "From" button.

• Click "Other email address..."
• Type the full email address of the email you would like to send as.
• Compose your email and click "Send"