Fetching gmail inbox mail messages via CDO in vba excel

Question

I would like to access the inbox in a gmail account using CDO in VBA. I have already managed to send a mail message but do not know how to fetch the inbox messages into an excel sheet. If possible I would like to be able to identify the tags of each message as well.

Answer 1

While the question asks for CDO in particular, from this similar SO question it doesn't look like this is possible directly with CDO.

As an alternative approach to fetching inbox mail messages, Google has recently released a Gmail API that could be consumed with Excel. Below is an example using VBA-Web:

' Setup client and authenticator (cached between requests)
Private pGmailClient As WebClient
Private Property Get GmailClient() As WebClient
    If pGmailClient Is Nothing Then
        ' Create client with base url that is appended to all requests
        Set pGmailClient = New WebClient
        pGmailClient.BaseUrl = "https://www.googleapis.com/gmail/v1/"

        ' Use the pre-made GoogleAuthenticator found in authenticators/ folder
        ' - Automatically uses Google's OAuth approach including login screen
        ' - Get API client id and secret from https://console.developers.google.com/
        ' - https://github.com/timhall/Excel-REST/wiki/Google-APIs for more info
        Dim Auth As New GoogleAuthenticator
        Auth.Setup "Your client id", "Your client secret"
        Auth.AddScope "https://www.googleapis.com/auth/gmail.readonly"
        Auth.Login
        Set pGmailClient.Authenticator = Auth
    End If

    Set GmailClient = pGmailClient
End Property

' Load messages for inbox
Function LoadInbox() As Collection
    Set LoadInbox = New Collection

    ' Create inbox request with userId and querystring for inbox label
    Dim Request As New WebRequest
    Request.Resource = "users/{userId}/messages"
    Request.AddUrlSegment "userId", "me"
    Request.AddQuerystringParam "q", "label:inbox"

    Dim Response As WebResponse
    Set Response = GmailClient.Execute(Request)

    If Response.StatusCode = WebStatusCode.Ok Then
        Dim MessageInfo As Dictionary
        Dim Message As Dictionary

        For Each MessageInfo In Response.Data("messages")
            ' Load full messages for each id
            Set Message = LoadMessage(MessageInfo("id"))
            If Not Message Is Nothing Then
                LoadInbox.Add Message
            End If
        Next MessageInfo
    End If
End Function

' Load message details
Function LoadMessage(MessageId As String) As Dictionary
    Dim Request As New WebRequest
    Request.Resource = "users/{userId}/messages/{messageId}"
    Request.AddUrlSegment "userId", "me"
    Request.AddUrlSegment "messageId", MessageId

    Dim Response As WebResponse
    Set Response = GmailClient.Execute(Request)

    If Response.StatusCode = WebStatusCode.Ok Then
        Set LoadMessage = New Dictionary

        ' Pull out relevant parts of message (from, to, and subject from headers)
        LoadMessage.Add "snippet", Response.Data("snippet")

        Dim Header As Dictionary
        For Each Header In Response.Data("payload")("headers")
            Select Case Header("name")
            Case "From"
                LoadMessage.Add "from", Header("value")
            Case "To"
                LoadMessage.Add "to", Header("value")
            Case "Subject"
                LoadMessage.Add "subject", Header("value")
            End Select
        Next Header
    End If
End Function

Sub Test()
    Dim Message As Dictionary
    For Each Message In LoadInbox
        Debug.Print "From: " & Message("from") & ", Subject: " & Message("subject")
        Debug.Print Message("snippet") & vbNewLine
    Next Message
End Sub