Sony Xperia User Manual page 185

Failed S! Mail/SMS messages are saved as drafts.
Sending S! Mail/SMS
Switching S! Mail/SMS
S! Mail and SMS switch automatically when sending, depending on whether there is a
subject, text length, etc.
Check with indication at the top of screen when creating a message.
When "S! Mail" appears, send as S! Mail.
When "SMS" appears, send as SMS.
To select
(Mail)
About Drafts
When
Drafts are indicated as
an S! Mail/SMS draft to edit and send it.
15
(S! Mail) or
Common Settings
is Tapped while creating S! Mail or SMS, the message is saved as a draft.
in thread list, and are saved to
(SMS) when creating mail, in Home Screen, Tap
SMS/S!Mail Automatic Switching ( ).
Draft Box in folder list. Open