Following is my Email option setting:

E-Mail Transport Method smtpauth
E-Mail Linefeeds LF
Use MIME HTML When Sending Emails true
Send E-Mails true
Email Archiving Active? true
E-Mail Friendly-Errors false
Email Address (Displayed to Contact you) xxx######################
Email Address (sent FROM) xxx######################
Emails must send from known domain? Yes
Email Admin Format? HTML
.
.
.
Set "Contact Us" Email Dropdown List
Allow Guest To Tell A Friend false
Contact Us - Show Store Name and Address 1
Send Low Stock Emails 0
Send Low Stock Emails To xxx######################
Display "Newsletter Unsubscribe" Link? false
Audience-Select Count Display false
SMTP Email Account Mailbox xxx######################
SMTP Email Account Password ***********
SMTP Email Mail Host smtp.gmail.com
SMTP Email Mail Server Port 465
Convert currencies for Text emails £,£:€,€



Then test to sign up, everything is fine. But I cannot find the welcome email from the test customer's mail box and FIND the welcome email from the Sent Mail of xxx######################(Which is used to fill the Email Option above.)

Anyone got any idea about it ? thx