(VB.NET UWP/WinRT) Mark IMAP Email as Read/Unread (Seen/Unseen)

Demonstrates how to mark emails as read or unread.

Chilkat Universal Windows Platform (UWP) / WinRT Downloads Chilkat for the Universal Windows Platform (UWP)

' 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 an IMAP server.
' Use TLS
imap.Ssl = True
imap.Port = 993
Dim success As Boolean = Await imap.ConnectAsync("imap.someMailServer.com")
If (success <> True) Then
    Debug.WriteLine(imap.LastErrorText)
    Exit Sub
End If


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


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


' Set PeekMode so that downloaded messages are not
' automatically marked as seen.
imap.PeekMode = True

' The NumMessages property contains the number of messages 
' in the currently selected mailbox.
Dim numMsgs As Integer = imap.NumMessages
If (numMsgs = 0) Then
    Exit Sub
End If


Dim i As Integer
For i = 1 To numMsgs
    ' Download each email by sequence number (not UID)
    Dim email As Chilkat.Email
    email = Await imap.FetchSingleAsync(i,False)
    If (imap.LastMethodSuccess = False) Then
        Debug.WriteLine(imap.LastErrorText)
        Exit Sub
    End If


    ' If desired, mark the email as SEEN.  There are two
    ' ways to do it:

    ' 1) Set the flag directly by using the sequence number
    ' Indicate that we are passing a sequence number and
    ' not a UID:
    Dim bIsUid As Boolean = False
    ' Set the SEEN flag = 1 to mark the email as SEEN,
    ' or set it to 0 to mark it as not-seen.
    success = Await imap.SetFlagAsync(i,bIsUid,"SEEN",1)
    If (success <> True) Then
        Debug.WriteLine(imap.LastErrorText)
        Exit Sub
    End If


    ' 2) Alternatively, we can use the email object.
    ' When an email is downloaded from the IMAP server
    ' Chilkat will add a "ckx-imap-uid" header to the email.
    ' This makes it possible to know the UID associated with
    ' the email.  (This is not the sequence number, which may change
    ' from session to session, but the UID which does not change.
    ' The SetMailFlag method is identical to SetFlag, except
    ' it gets the UID from the ckx-imap-uid header.
    ' For example:
    success = Await imap.SetMailFlagAsync(email,"SEEN",1)
    If (success <> True) Then
        Debug.WriteLine(imap.LastErrorText)
        Exit Sub
    End If





Next


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