(VB.NET) Read IMAP Email Headers

Call FetchHeaders to download only the email headers.

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

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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 to an IMAP server.
' Use 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


' Login
success = imap.Login("****","****")
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


' Get the message IDs of all the emails in the mailbox
' We can choose to fetch UIDs or sequence numbers.
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


' When downloading headers, each email object contains
' (obviously) the headers, but the body will be missing.
' Also, attachments will not be included.  However, it is
' possible to get information about the attachments
' as well as the complete size of the email.
Dim bundle As New Chilkat.EmailBundle
Dim headersOnly As Boolean = True
success = imap.FetchMsgSet(headersOnly,messageSet,bundle)
If (success = False) Then
    Debug.WriteLine(imap.LastErrorText)
    Exit Sub
End If


' Loop over the email objects and display information
' about each:
Dim email As New Chilkat.Email
Dim name As String
Dim addr As String
Dim i As Integer = 0
Dim j As Integer = 0
While i < bundle.MessageCount
    bundle.EmailAt(i,email)

    ' Display the From and Subject
    Debug.WriteLine(email.From)
    Debug.WriteLine(email.Subject)

    ' Display the recipients:
    j = 0
    While j < email.NumTo
        Debug.WriteLine("TO: " & email.GetToName(j) & ", " & email.GetToAddr(j))
        j = j + 1
    End While
    j = 0
    While j < email.NumCC
        Debug.WriteLine("CC: " & email.GetCcName(j) & ", " & email.GetCcAddr(j))
        j = j + 1
    End While

    ' Show the total size of the email, including body and attachments:
    Debug.WriteLine(email.Size)

    ' When a full email is downloaded, we would use the
    ' email.NumAttachments property in conjunction with the
    ' email.GetMailAttach* methods.
    ' However, when an email object contains only the header,
    ' we need to access the attachment info differently:
    Dim numAttach As Integer = imap.GetMailNumAttach(email)
    j = 0
    While j < numAttach
        Debug.WriteLine(imap.GetMailAttachFilename(email,j))
        Dim attachSize As Integer = imap.GetMailAttachSize(email,j)
        Debug.WriteLine("    size = " & attachSize & " bytes")
        j = j + 1
    End While

    Debug.WriteLine("--")
End While

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