(VB.NET) How to Download Messages in MessageSet One at a Time

If a message set contains a huge number of emails, it's NOT a good idea to try to download all at once into an email bundle using a method such as FetchBundle. It's better to iterate over the messages in the set to download one by one.

Note: This example requires Chilkat v11.0.0 or greater.

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

Dim success As Boolean = False

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

Dim imap As New Chilkat.Imap

' Connect using TLS.
imap.Ssl = True
imap.Port = 993
success = imap.Connect("imap.example.com")
If (success = False) Then
    Debug.WriteLine(imap.LastErrorText)
    Exit Sub
End If


' Authenticate
success = imap.Login("email_account_login","email_account_password")
If (success = False) Then
    Debug.WriteLine(imap.LastErrorText)
    Exit Sub
End If


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


' Search for messages and return a set of matching messages.
' (This example will simply search for ALL messages.)
Dim fetchUids As Boolean = True

Dim messageSet As New Chilkat.MessageSet
success = imap.QueryMbx("ALL",fetchUids,messageSet)
If (success = False) Then
    Debug.WriteLine(imap.LastErrorText)
    Exit Sub
End If


Debug.WriteLine("Number of messages = " & messageSet.Count)

Dim email As New Chilkat.Email
Dim i As Integer = 0
While i < messageSet.Count
    success = imap.FetchEmail(False,messageSet.GetId(i),fetchUids,email)
    If (success = False) Then
        Debug.WriteLine(imap.LastErrorText)
        Exit Sub
    End If


    Debug.WriteLine(email.From & "; " & email.Subject)

    i = i + 1
End While

Debug.WriteLine("OK")