Mouse: select email in list so it displays message in Message Pane click on the 'From' email address and click on eg: 'Copy email address' OR combi of mouse and keyboard click on the 'From' email address to see drop down and then press 'C' key to copy Or keyboard use the 'tab' key until 'From' is highlighted in an opened email, then use the key icon for right click - usually located next to the Ctrl key on the right side of keyboard - to show drop down list and then press 'C' key General info on shortcuts: https://support.mozilla.org/en-US/kb/keyboard-shortcuts-thunderbird