Simply posting the quotes or even uploading a picture, can be counted as invalid (since those can be manipulated).
Two ways (that I'm aware of) that you can provide proof without manipulating/changing the evidence:
1. Take a video and post it online.
2. Go on the email you received on gmail > Upper right corner, click the drop down button > Print > Change its destination to "Save to Google Drive" > Save > Go to your google drive and right click on that file > Get shareable link and post it here.
- Take note: By doing this, the name you have on your gmail account will be shown as well (if you're not comfortable with sharing it, then take a video instead).