Mobile email usage is increasing significantly, with the number of worldwide mobile email users expected to double from 897 million in 2013 to 1.8 billion in 2017. Most emails are now opened on smartphones, with 66% opened on smartphones or tablets and 47% opened specifically on iPhones. Email open rates were highest when subject lines were between 6 to 10 words.

1. were
19%
opened on
TABLETS
smartphones
or tablets. SMARTPHONES
8
66%
OF EMAILS
Worldwide
mobile email
users are
expected to
double from
897
MILLION IN
2013 TO
BILLION
Sources: Moveable Ink US Consumer Device Preference Report; Litmus; Retention Science; Radicati Group, Email Statistics Report, 2013-2017
47%
IN
2017.
of all emails
are opened
on iPhones. 25%
The highest open rates
were subject lines limited to
6 TO 10 WORDS.