Android Question fail whit smtp in b4a ?

Hello,
In the log of application, say me :
UNDECLARED VARIABLE 'SMTP' IS USED BEFORE IT WAS ASSIGNED ANY VALUE


Sub Process_Globals
Dim SMTP As SMTP
Dim GPS1 As GPS
'Dim FTP As FTP
Dim PH As Phone
Dim pi As PhoneId


Private frontCamera As Boolean = False
End Sub

And i can not used the smtp for send email

why, please?

thanks