(Excel) IMAP Download and Verify Signed (S/MIME) Email

Demonstrates how to download and verify digitally signed S/MIME email.

Download Excel Class Modules Chilkat Excel Class Modules

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

Dim imap As Chilkat.Imap
Set imap = Chilkat.NewImap

' Connect to an IMAP server.
' Use TLS
imap.Ssl = True
imap.Port = 993

success = imap.Connect("imap.someMailServer.com")
If (success <> True) Then
    Debug.Print imap.LastErrorText
    Exit Sub
End If

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

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

' We can choose to fetch UIDs or sequence numbers.

fetchUids = True

' Get the message IDs of all the emails in the mailbox

Set messageSet = imap.Search("ALL",fetchUids)
If (imap.LastMethodSuccess <> True) Then
    Debug.Print imap.LastErrorText
    Exit Sub
End If

' Scan for emails with attachments, and save the attachments
' to a sub-directory.

i = 0
Do While i < messageSet.Count


    uid = messageSet.GetId(i)
    Debug.Print "uid: "; uid


    Set email = imap.FetchSingle(uid,True)

    ' The security layers of signed and/or encrypted emails
    ' are automatically "unwrapped" when loaded into
    ' a Chilkat email object.
    ' An application only needs to check to see if an email
    ' was received signed or encrypted, and then examine
    ' the success/failure.  For example:
    If (email.ReceivedSigned = True) Then

        Debug.Print "This email was signed."

        ' Check to see if the signatures were verified.
        If (email.SignaturesValid = True) Then
            Debug.Print "Digital signature(s) verified."

            Debug.Print "Signer: "; email.SignedBy

            ' The certificate used for signing may be obtained
            ' by calling email.GetSignedByCert.

            Set cert = email.GetSignedByCert()
            If (email.LastMethodSuccess <> True) Then
                Debug.Print "Failed to get signing certificate object."
            Else
                Debug.Print "Signing cert: "; cert.SubjectCN

            End If

        Else
            Debug.Print "Digital signature verification failed."
        End If

    End If

    i = i + 1
Loop

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