POS Defaults are set to email where possible and the receipt printer is set to Always Print and Docket (40 column).
The email attachment created was a Docket on an A4 PDF.
If the POS defaults are set to Docket(40 column) it will use POS1 as the email layout.
To change the layout used, change the default to True Type and selecting the layout save the defaults screen. Once it saved you can go back in and change it back to docket and it will remember the selected layout for emailing.
If you are using True type for receipts then it will just use the selected layout.