FAQ.How can I validate an email address?
Feedback.

Answer: You can try this code:
Example:

Dim re As RegEx
re = New RegEx
Dim rm As RegExMatch

re.SearchPattern = "[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?"
rm = re.Search(editField1.Text)

if rm = Nil Then
  StaticText2.text = editField1.Text + " not valid email"
Else
  StaticText2.Text = editField1.Text + " is valid"
End if

Notes:
Adapted from:
http://www.regular-expressions.info/email.html