(Go) 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.

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

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

    http := chilkat.NewHttp()

    // 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).

    jsonToken := chilkat.NewJsonObject()
    success := jsonToken.LoadFile("qa_data/tokens/microsoftGraph.json")
    if success == false {
        fmt.Println(jsonToken.LastErrorText())
        http.DisposeHttp()
        jsonToken.DisposeJsonObject()
        return
    }

    http.SetAuthToken(*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
    email := chilkat.NewEmail()
    email.SetSubject("Test Outlook API to Send HTML Email with Attachments")
    email.SetFrom("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.
    contentIdStarfish := email.AddRelatedFile("qa_data/jpg/starfish.jpg")
    if email.LastMethodSuccess() != true {
        fmt.Println(email.LastErrorText())
        http.DisposeHttp()
        jsonToken.DisposeJsonObject()
        email.DisposeEmail()
        return
    }

    // The src attribute for the image tag is set to the contentIdStarfish:
    sbHtml := chilkat.NewStringBuilder()
    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>")
    numReplacements := 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 != true {
        fmt.Println(email.LastErrorText())
        http.DisposeHttp()
        jsonToken.DisposeJsonObject()
        email.DisposeEmail()
        sbHtml.DisposeStringBuilder()
        return
    }

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

    // Get the email as multi-line base64..
    bdMime := chilkat.NewBinData()
    email.GetMimeBd(bdMime)

    // Now get it as multi-line base64
    sbBase64 := chilkat.NewStringBuilder()
    bdMime.GetEncodedSb("base64_mime",sbBase64)

    // Send the HTTP POST (i.e. send the email)
    resp := http.PTextSb("POST","https://graph.microsoft.com/v1.0/me/sendMail",sbBase64,"utf-8","text/plain",false,false)
    if http.LastMethodSuccess() != true {
        fmt.Println(http.LastErrorText())
        http.DisposeHttp()
        jsonToken.DisposeJsonObject()
        email.DisposeEmail()
        sbHtml.DisposeStringBuilder()
        bdMime.DisposeBinData()
        sbBase64.DisposeStringBuilder()
        return
    }

    // 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 {
        json := chilkat.NewJsonObject()
        json.Load(resp.BodyStr())
        json.SetEmitCompact(false)
        fmt.Println(*json.Emit())
        fmt.Println("Failed, response status code = ", resp.StatusCode())
    }
    else {
        fmt.Println("Outlook Mail Sent.")
    }

    resp.DisposeHttpResponse()

    http.DisposeHttp()
    jsonToken.DisposeJsonObject()
    email.DisposeEmail()
    sbHtml.DisposeStringBuilder()
    bdMime.DisposeBinData()
    sbBase64.DisposeStringBuilder()
    json.DisposeJsonObject()