Resend an email to a different email address or with different content

In Mail, click the All Sent or Sent folder:

Click on the email thread that you want to re-send an email from:

Click on the message that you want to resend:

Click on the Message item in the menu bar at the top and then Send Again:

This will open a version of the email where you can change the To address and / or the content:

Once you’ve done that, click the send button as normal.