Strengthening email theming

[teolemon]

Story

[john-gom]

Hi @teolemon , the email now looks like this:

Is there anything more we'd want to change?

[teolemon]

I would add: if you keep receiving those email, please send a mail to contact@openfoodfacts.org , so that we get a mail from one of the users if something is really wrong ( like mass spam or restes)