This a QR Code image.
You may have the automatic downloading of images switched off. This can be a good idea if you want to save on mobile data usage but every now and again you may want to see the image.
These are the instructions for Android devices and Gmail.
support.google.com/mail/answer/145919?hl=en-GB&co=GENIE.Platform%3DAndroid
1. On your Android phone or tablet, open the Gmail app .
2. At the top left, tap Menu Menu.
3. Tap Settings and then your account.
4. Under 'Data usage', tap Images.
5. Tap Always show.
Note the other options for Computer, iPhones and iPads.
Other mail servers will be slightly different. Just look for settings and turn on display external images. Hotmail, for example:
Open the email; click “open message”; click “show content” at the top of the message. Click the Mail menu, then click Mail Settings. Click the “Hide images & disable links in mail from unknown senders” box to clear it. Click the “Save” button.
The Post Office will then be able to see and scan the QR Code and print a label for you.
If you have a home printer and would like the parcel collected you can print your own label and have Evri collect the parcel. Instructions here:
www.marksandspencer.com/c/help/returns-and-refunds/paperless-returns