Text email. HTML email provides access to a vast attack surface on the user's device. Normally webmail clients will cheerfully send along all the HTML. Filterin

Text email. HTML email provides access to a vast attack surface on the user's device. Normally webmail clients will cheerfully send along all the HTML. Filtering is a futile game of whack a mole. If you are only doing text email (or some very restricted HTML interpretation) then there is no extra risk in using a local email client. The lack of a HTML interpreter probably means you would be safer than with a webmail client. If you are doing some form of email as a precaution, you still need a secure place to do it. That might not be a typical smart phone.