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VB.NET

Yahoo! IMAP (imap.mail.yahoo.com)

(from Wikipedia)
It is possible to get direct IMAP access without signing up for paid access nor using software like YPOPs! or FreePOPs. Yahoo! operates IMAP and secure IMAP servers (imap.mail.yahoo.com in particular), which are globally accessible. However they require a specific, non-standard IMAP command to be sent before login is done, namely: “ID ("GUID" "1")”.
This example demonstrates sending the non-standard IMAP command after connecting but before login.

Chilkat VB.NET Downloads

VB.NET
Dim success As Boolean = False

' This example assumes the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.

Dim imap As New Chilkat.Imap

' Connect to they Yahoo! IMAP server.
imap.Port = 993
imap.Ssl = True
success = imap.Connect("imap.mail.yahoo.com")
If (success <> True) Then
    Debug.WriteLine(imap.LastErrorText)
    Exit Sub
End If


' Send the non-standard ID command...
Dim rawResponse As String
rawResponse = imap.SendRawCommand("ID (""GUID"" ""1"")")
If (imap.LastMethodSuccess <> True) Then
    Debug.WriteLine(imap.LastErrorText)
    Exit Sub
End If


' Login
success = imap.Login("myLogin","myPassword")
If (success <> True) Then
    Debug.WriteLine(imap.LastErrorText)
    Exit Sub
End If


Debug.WriteLine("Login Success!")

' Select an IMAP mailbox
success = imap.SelectMailbox("Inbox")
If (success <> True) Then
    Debug.WriteLine(imap.LastErrorText)
    Exit Sub
End If


' Continue with whatever you wish to do...
' (see other examples..)

' Disconnect from the IMAP server.
success = imap.Disconnect()