Smartphones are taking over the world and we see more emails with the familiar ‘Sent from my iPhone’ signature.
Lifehacker has a good article on Email Annoyances that is worth a read.
For those who would like the executive summary, one best practice might be to have a line like
‘Sent from my mobile. Please excuse the brevity, spelling and punctuation.’
I use ‘Sent from Handheld. Please ignore any typos’ myself.
A Learning a Day 