(VB.NET) Outlook Send Email using MIME Format

See more Outlook Examples

This example sends an email using MIME format via the Microsoft Graph Outlook REST API.

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

For more information, see https://learn.microsoft.com/en-us/graph/api/user-sendmail?view=graph-rest-1.0&tabs=http#example-4-send-a-new-message-using-mime-format

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 http As New Chilkat.Http

' Use your previously obtained access token here:
' See the following examples for getting an access token:
'    Get Microsoft Graph OAuth2 Access Token (Azure AD v2.0 Endpoint).
'    Get Microsoft Graph OAuth2 Access Token (Azure AD Endpoint).
'    Refresh Access Token (Azure AD v2.0 Endpoint).
'    Refresh Access Token (Azure AD Endpoint).

Dim jsonToken As New Chilkat.JsonObject
success = jsonToken.LoadFile("qa_data/tokens/microsoftGraph.json")
If (success = False) Then
    Debug.WriteLine(jsonToken.LastErrorText)
    Exit Sub
End If


http.AuthToken = jsonToken.StringOf("access_token")

' To send email, we'll POST to the following endpoint:
' 
' POST /users/{id | userPrincipalName}/sendMail
' 
' (The special keyword "me" may be used in place of a principal name.)
' 

' The body of the POST request will contain the MIME source of the email in base64 format.

' Create a new email object
Dim email As New Chilkat.Email
email.Subject = "Test Outlook API to Send HTML Email with Attachments"
email.From = "Mary <mary@somewhere.com>"
email.AddTo("Joe","joe@example.com")

' Add a plain-text alternative body, which will likely never be seen.
' (It is shown if the receiving email client is incapable of displaying HTML email.)
email.AddPlainTextAlternativeBody("This is a plain-text alternative body...")

' Our HTML will include an image, so add the related image here.
Dim contentIdStarfish As String = email.AddRelatedFile("qa_data/jpg/starfish.jpg")
If (email.LastMethodSuccess = False) Then
    Debug.WriteLine(email.LastErrorText)
    Exit Sub
End If


' The src attribute for the image tag is set to the contentIdStarfish:
Dim sbHtml As New Chilkat.StringBuilder
sbHtml.Append("<html><body><p>This is an HTML email with an embedded image.</p>")
sbHtml.Append("<p><img src=""cid:CONTENT_ID_STARFISH"" /></p></body></html>")
Dim numReplacements As Integer = sbHtml.Replace("CONTENT_ID_STARFISH",contentIdStarfish)

email.AddHtmlAlternativeBody(sbHtml.GetAsString())

' Finally, add some attachments to the email.
' Add a file attachment.
success = email.AddFileAttachment2("qa_data/pdf/fishing.pdf","application/pdf")
If (success = False) Then
    Debug.WriteLine(email.LastErrorText)
    Exit Sub
End If


' Add an attachment where the content is contained in a string.
Dim content As String = "This is the content of the 2nd attached file."
email.AddStringAttachment("someText.txt",content)

' Get the email as multi-line base64..
Dim bdMime As New Chilkat.BinData
email.GetMimeBd(bdMime)

' Now get it as multi-line base64
Dim sbBase64 As New Chilkat.StringBuilder
bdMime.GetEncodedSb("base64_mime",sbBase64)

' Send the HTTP POST (i.e. send the email)
Dim resp As New Chilkat.HttpResponse
success = http.HttpSb("POST","https://graph.microsoft.com/v1.0/me/sendMail",sbBase64,"utf-8","text/plain",resp)
If (success = False) Then
    Debug.WriteLine(http.LastErrorText)
    Exit Sub
End If


' The send succeeded if the response status code = 202.
' In the success case, there is no response body.  (We just get the response code to know that it succeeded.)
If (resp.StatusCode <> 202) Then
    Dim json As New Chilkat.JsonObject
    json.Load(resp.BodyStr)
    json.EmitCompact = False
    Debug.WriteLine(json.Emit())
    Debug.WriteLine("Failed, response status code = " & resp.StatusCode)
Else
    Debug.WriteLine("Outlook Mail Sent.")
End If