(VB.NET) Copy Email from one IMAP Account to Another

Demonstrates how to copy the email in a mailbox from one account to another.

Chilkat .NET Downloads Chilkat .NET Framework Chilkat for .NET Core

Dim imapSrc As New Chilkat.Imap

' This example assumes Chilkat Imap to have been previously unlocked.
' See Unlock Imap for sample code.

' Connect to our source IMAP server.
imapSrc.Ssl = True
imapSrc.Port = 993
Dim success As Boolean = imapSrc.Connect("MY-IMAP-DOMAIN")
If (success <> True) Then
    Debug.WriteLine(imapSrc.LastErrorText)
    Exit Sub
End If


' Login to the source IMAP server
success = imapSrc.Login("MY-IMAP-LOGIN","MY-IMAP-PASSWORD")
If (success <> True) Then
    Debug.WriteLine(imapSrc.LastErrorText)
    Exit Sub
End If


Dim imapDest As New Chilkat.Imap

' Connect to our destination IMAP server.
imapDest.Ssl = True
imapDest.Port = 993
success = imapDest.Connect("MY-IMAP-DOMAIN2")
If (success <> True) Then
    Debug.WriteLine(imapDest.LastErrorText)
    Exit Sub
End If


' Login to the destination IMAP server
success = imapDest.Login("MY-IMAP-LOGIN2","MY-IMAP-PASSWORD2")
If (success <> True) Then
    Debug.WriteLine(imapDest.LastErrorText)
    Exit Sub
End If


' Select a source IMAP mailbox on the source IMAP server
success = imapSrc.SelectMailbox("Inbox")
If (success <> True) Then
    Debug.WriteLine(imapSrc.LastErrorText)
    Exit Sub
End If


Dim fetchUids As Boolean = True

' Get the set of UIDs for all emails on the source server.
Dim mset As Chilkat.MessageSet = imapSrc.Search("ALL",fetchUids)
If (imapSrc.LastMethodSuccess <> True) Then
    Debug.WriteLine(imapSrc.LastErrorText)
    Exit Sub
End If



' Load the complete set of UIDs that were previously copied.
' We dont' want to copy any of these to the destination.
Dim fac As New Chilkat.FileAccess
Dim msetAlreadyCopied As New Chilkat.MessageSet
Dim strMsgSet As String = fac.ReadEntireTextFile("qa_cache/saAlreadyLoaded.txt","utf-8")
If (fac.LastMethodSuccess = True) Then
    msetAlreadyCopied.FromCompactString(strMsgSet)
End If


Dim numUids As Integer = mset.Count
Dim sbFlags As New Chilkat.StringBuilder

Dim i As Integer = 0
While i < numUids

    ' If this UID was not already copied...
    Dim uid As Integer = mset.GetId(i)
    If (Not msetAlreadyCopied.ContainsId(uid)) Then

        Debug.WriteLine("copying " & uid & "...")

        ' Get the flags.
        Dim flags As String = imapSrc.FetchFlags(uid,True)
        If (imapSrc.LastMethodSuccess = False) Then
            Debug.WriteLine(imapSrc.LastErrorText)
            Exit Sub
        End If

        sbFlags.SetString(flags)

        ' Get the MIME of this email from the source.
        Dim mimeStr As String = imapSrc.FetchSingleAsMime(uid,True)
        If (imapSrc.LastMethodSuccess = False) Then
            Debug.WriteLine(imapSrc.LastErrorText)
            Exit Sub
        End If


        Dim seen As Boolean = sbFlags.Contains("\Seen",False)
        Dim flagged As Boolean = sbFlags.Contains("\Flagged",False)
        Dim answered As Boolean = sbFlags.Contains("\Answered",False)
        Dim draft As Boolean = sbFlags.Contains("\Draft",False)

        success = imapDest.AppendMimeWithFlags("Inbox",mimeStr,seen,flagged,answered,draft)
        If (success <> True) Then
            Debug.WriteLine(imapDest.LastErrorText)
            Exit Sub
        End If


        ' Update msetAlreadyCopied with the uid just copied.
        msetAlreadyCopied.InsertId(uid)

        ' Save at every iteration just in case there's a failure..
        strMsgSet = msetAlreadyCopied.ToCompactString()
        fac.WriteEntireTextFile("qa_cache/saAlreadyLoaded.txt",strMsgSet,"utf-8",False)
    End If


    i = i + 1
End While


' Disconnect from the IMAP servers.
success = imapSrc.Disconnect()
success = imapDest.Disconnect()