From now on you can easily copy an email address and paste it in the correct field.
In this case, just do as follows:
- mark with your mouse the address you want to copy. Remember to mark the address only, without its name and without special characters like < > or " ".
- copy marked address by clicking on the right mouse button (or by using shortcuts ctrl+c; cmd+c)
- paste it in the select field (or with the shortcuts ctrl+v; cmd+v)