How do I send a gmail email in vb.net? - vb.net

Question

I want to send an email, but it gives me an error.
I have this code:
Sub sendMail(ByVal title As String, ByVal content As String)
Dim SmtpServer As New SmtpClient("smtp.gmail.com", 25)
SmtpServer.Credentials = New Net.NetworkCredential("name#gmail.com", "password")
Dim mail As New MailMessage("name#gmail.com", "name#gmail.com", title, content)
SmtpServer.Send(mail)
End Sub
I have a try catch which tries to call this method, it doesnt work so the catch runs and i get thes exception: System.Net.Mail.SmtpException: The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.7.0 Must issue a STARTTLS command first. b6sm3176487lae.0 - gsmtp Why do I get this error? and how do I fix it?

Answer 1

Gmail uses SMTP over SSL on port 465.
Try doing:
Dim SmtpServer As New SmtpClient("smtp.gmail.com", 465)
...
SmtpServer.EnableSsl = True
...

Answer 2

Try this - I know it works.
Dim Mail As New MailMessage
Dim SMTP As New SmtpClient("smtp.gmail.com")
Mail.Subject = "Security Update"
Mail.From = New MailAddress("name#gmail.com")
SMTP.Credentials = New System.Net.NetworkCredential("name#gmail.com", "password") '<-- Password Here
Mail.To.Add(address & "#gmail.com") 'I used ByVal here for address
Mail.Body = "" 'Message Here
SMTP.EnableSsl = True
SMTP.Port = "587"
SMTP.Send(Mail)

Answer 3

There is some problem with google account, you need to switch off some security settings. After sending email over and over, I received email on one of my support account (for google), the email were:
You recently changed your security settings so that your Google Account [trdjoko#gmail.com] is no longer protected by modern security standards.
If you did not make this change
Please review your Account Activity page at https://security.google.com/settings/security/activity to see if anything looks suspicious. Whoever made the change knows your password; we recommend that you change it right away.
If you made this change
Please be aware that it is now easier for an attacker to break into your account. You can make your account safer again by undoing this change at https://www.google.com/settings/security/lesssecureapps then switching to apps made by Google such as Gmail to access your account.
Sincerely,
The Google Accounts team
So I switched of additional security and i worked fine.

Answer 4

Change the port to 587. Port 25 does not support SSL.

Answer 5

A super easy way of doing this(without changing any security settings) is by using IFTTT and my IFTTT Maker.net libary
First, in IFTTT create a new recipe that's triggered by the Maker channel and name the event "send_gmail".
Then, select the Gmail engine and click "Send an email", and replace To with {{value1}}, subject with {{value2}} and message/body with {{value3}}
After that, in Visual studio, add ifttt.vb to your project. Now for the code:
Try
makechannel.scode = "your account ID"
makechannel.fireevent("send_gmail", "TO", "SUBJECT", "MESSAGE")
'code goes here if done
Catch ex As Exception
'code goes here if it fails
End Try
Then fill in your account ID. You can find it at ifttt.com/maker
And that's it!

Answer 6

I Have written the class which can perform this task easyly.
Imports System.Net.Mail
Public Class GGSMTP_GMAIL
Dim Temp_GmailAccount As String
Dim Temp_GmailPassword As String
Dim Temp_SMTPSERVER As String
Dim Temp_ServerPort As Int32
Dim Temp_ErrorText As String = ""
Dim Temp_EnableSSl As Boolean = True
Public ReadOnly Property ErrorText() As String
Get
Return Temp_ErrorText
End Get
End Property
Public Property EnableSSL() As Boolean
Get
Return Temp_EnableSSl
End Get
Set(ByVal value As Boolean)
Temp_EnableSSl = value
End Set
End Property
Public Property GmailAccount() As String
Get
Return Temp_GmailAccount
End Get
Set(ByVal value As String)
Temp_GmailAccount = value
End Set
End Property
Public Property GmailPassword() As String
Get
Return Temp_GmailPassword
End Get
Set(ByVal value As String)
Temp_GmailPassword = value
End Set
End Property
Public Property SMTPSERVER() As String
Get
Return Temp_SMTPSERVER
End Get
Set(ByVal value As String)
Temp_SMTPSERVER = value
End Set
End Property
Public Property ServerPort() As Int32
Get
Return Temp_ServerPort
End Get
Set(ByVal value As Int32)
Temp_ServerPort = value
End Set
End Property
Public Sub New(ByVal GmailAccount As String, ByVal GmailPassword As String, Optional ByVal SMTPSERVER As String = "smtp.gmail.com", Optional ByVal ServerPort As Int32 = 587, Optional ByVal EnableSSl As Boolean = True)
Temp_GmailAccount = GmailAccount
Temp_GmailPassword = GmailPassword
Temp_SMTPSERVER = SMTPSERVER
Temp_ServerPort = ServerPort
Temp_EnableSSl = EnableSSl
End Sub
Public Function SendMail(ByVal ToAddressies As String(), ByVal Subject As String, ByVal BodyText As String, Optional ByVal AttachedFiles As String() = Nothing) As Boolean
Temp_ErrorText = ""
Dim Mail As New MailMessage
Dim SMTP As New SmtpClient(Temp_SMTPSERVER)
Mail.Subject = Subject
Mail.From = New MailAddress(Temp_GmailAccount)
SMTP.Credentials = New System.Net.NetworkCredential(Temp_GmailAccount, Temp_GmailPassword) '<-- Password Here
Mail.To.Clear()
For i As Int16 = 0 To ToAddressies.Length - 1
Mail.To.Add(ToAddressies(i))
Next i
Mail.Body = BodyText
Mail.Attachments.Clear()
If AttachedFiles IsNot Nothing Then
For i As Int16 = 0 To AttachedFiles.Length - 1
Mail.Attachments.Add(New Attachment(AttachedFiles(i)))
Next
End If
SMTP.EnableSsl = Temp_EnableSSl
SMTP.Port = Temp_ServerPort
Try
SMTP.Send(Mail)
Return True
Catch ex As Exception
Me.Temp_ErrorText = ex.Message.ToString
Return False
End Try
End Function
End Class
Its the way, how to use class:
Dim GGmail As New GGSMTP_GMAIL("MyFromAddress1#gmail.com", "AccPassword", )
Dim ToAddressies As String() = {"ToAddress1#gmail.com", "ToAddress2#gmail.com"}
Dim attachs() As String = {"d:\temp_Excell226.xlsx", "d:\temp_Excell224.xlsx", "d:\temp_Excell225.xlsx"}
Dim subject As String = "My TestSubject"
Dim body As String = "My text goes here ...."
Dim result As Boolean = GGmail.SendMail(ToAddressies, subject, body, attachs)
If result Then
MsgBox("mails sended successfully", MsgBoxStyle.Information)
Else
MsgBox(GGmail.ErrorText, MsgBoxStyle.Critical)
End If
Hope this helps. Good coding