Smail is a mail transfer agent used on Unix-like operating systems.
Smail may also refer to: Snail mail, a disparaging retronym referring to missives carried by conventional postal delivery services Robert Smail's Printing Works, a Victorian-era letterpress printing works in the Scottish Borders town of Innerleithen
People with the surname David Smail (golfer) (born 1970), New Zealand professional golfer David Smail (psychologist) (born 1938), British clinical psychologist Doug Smail (born 1957), Canadian ice hockey left winger John R.W. Smail (1930-2002), Cornell historian of Southeast Asia Thomas Smail (born 1928), Scottish theologian