Sending eMail using SMTP Gmail yahoo hotmail in Visual Basic 2010

Imports System.Net.Mail

Public Class Form1


Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim msg As String
Dim feedback As String

msg = "Sender's Name: " & tbName.Text
msg = msg + vbCrLf
msg = msg + "Sender's email Address: " & tbEmail.Text


feedback = SendEmailMessage("your email@gmail.com", "your email@gmail.com", "your password", "Phone Unlock Enquiry", msg)
feedback = feedback + vbCrLf + "In order to help improve our services, please feel free to donate by send us a paypal or Western Union."
feedback = feedback + vbCrLf + "Thank you for using our free software. We will get back to you within 48 hours."

End Sub




Function SendEmailMessag(ByVal sendTo As String, _
ByVal sendFrom As String, _
ByVal password As String, _
ByVal sendSubject As String, _
ByVal sendMessage As String) As String

Try

' validate recipient email address
Dim bTest As Boolean = ValidateEmailAddress(sendTo)

If (bTest = False) Then
Return "Invalid recipient email address: " + sendTo
End If

' validate sender email address
bTest = ValidateEmailAddress(sendFrom)

If (bTest = False) Then
Return "Invalid sender email address: " + sendTo
End If

' Create the basic message
Dim message As New MailMessage( _
sendFrom, _
sendTo, _
sendSubject, _
sendMessage)

' create smtp client at mail server location
Dim client As New SmtpClient()

' Add credentials
client.Credentials = New System.Net.NetworkCredential(sendFrom, password)
client.Port = 587
client.Host = "smtp.gmail.com"

' send message
client.Send(message)

Return "Message sent to " + sendTo + " at " +
DateTime.Now.ToString() + "."

Catch ex As Exception

Return ex.Message.ToString()

End Try

End Function


Function ValidateEmailAddress(ByVal emailAddress As String) As Boolean

Try

Dim TextToValidate As String = emailAddress
Dim expression As New Regex("\w+@[a-zA-Z_]+?\.[a-zA-Z]{2,3}")

' test email address with expression
If (expression.IsMatch(TextToValidate)) Then
' is valid email address
Return True
Else
' is not valid email address
Return False
End If

Catch ex As Exception

Throw ex

End Try

End Function