Google ANDROID 2.3.4 - Manual (Page 227)

Email 227
AUG-2.3.4-105 Android User’s Guide
Require sign-in
Check this option to enter a username and
password for your SMTP server, if your email
service provider requires that you enter them to
send email.
Username
Your username on the SMTP server (this may
not be the same as your username on the
POP3 or IMAP server for incoming mail). Visible
only if Require sign-in is checked.
Password
Your password on the SMTP server (this may
not be the same as your username on the
POP3 or IMAP server for incoming mail). Visible
only if Require sign-in is checked.