Working Americans spend almost a third of the workweek checking and reading email. In a 40-hour week, that’s over 11 hours a week reading online communications in fonts that aren’t doing our eyes any favors. Recent studies have considered the readability of fonts for business — including emails.
Having considered these options, I have changed my email font to a relatively new font called “Input”. A sample is below:

Hopefully, my clients will find email communications easier to read! You can download it – for free – here.