I am not sure most people realise that they are advertising their telephone or tablet brand when sending emails using them.
Most messages / emails sent automatically signs “Sent from my iPhone”. The same is valid for Samsung, Huawei etc.
I personally do not think this should be allowed unless of course Apple and company pays you some money for it.
It is easy enough to get rid of the message and replace it with your own signature message.
I encourage people to do this and stop these corporations taking unfair advantage