Rust
Outlook Send HTML Email with Embedded Images

This example sends an HTML email with embedded images. Other examples exist for:
Sending plain-text email.
Sending email with attachments.
Sending HTML email with embedded images and attachments.
Chilkat Rust Downloads

Rust

// Important: This example requires Chilkat v9.5.0.68 or greater.

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

let http = chilkat::Http::new();

// 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).

http.set_auth_token("MICROSOFT_GRAPH_ACCESS_TOKEN");

// To send mail, 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.)
// 

// This example will send HTML email containing the following HTML body.
// After the 

// 	<html>
// 	<head>
// 	<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
// 	<meta content="text/html; charset=utf-8">
// 	</head>
// 	<body bgcolor="#FFFFFF">
// 	<font face="Calibri">This is a test <b>HTML email with embedded images</b>.<br>
// 	<br>
// 	<img alt="" src="cid:starfish"><br>
// 	<img alt="" src="cid:hedgehogs"><br>
// 	</font>
// 	</body>
// 	</html>

// Build the HTML body...
let b_crlf = true;
let sb_html_body = chilkat::StringBuilder::new();
let _ = sb_html_body.append_line("<html>", b_crlf);
let _ = sb_html_body.append_line("<head>", b_crlf);
let _ = sb_html_body.append_line("<meta http-equiv=\"Content-Type\" content=\"text/html; charset=utf-8\">", b_crlf);
let _ = sb_html_body.append_line("<meta content=\"text/html; charset=utf-8\">", b_crlf);
let _ = sb_html_body.append_line("</head>", b_crlf);
let _ = sb_html_body.append_line("<body bgcolor=\"#FFFFFF\">", b_crlf);
let _ = sb_html_body.append_line("<font face=\"Calibri\">This is a test <b>HTML email with embedded images</b>.<br>", b_crlf);
let _ = sb_html_body.append_line("<br>", b_crlf);
let _ = sb_html_body.append_line("<img alt=\"\" src=\"cid:starfish\"><br>", b_crlf);
let _ = sb_html_body.append_line("<img alt=\"\" src=\"cid:hedgehogs\"><br>", b_crlf);
let _ = sb_html_body.append_line("</font>", b_crlf);
let _ = sb_html_body.append_line("</body>", b_crlf);
let _ = sb_html_body.append_line("</html>", b_crlf);

// Load the image files.
let jpg_starfish = chilkat::BinData::new();
let _ = jpg_starfish.load_file("qa_data/jpg/starfish.jpg");
let jpg_hedge_hogs = chilkat::BinData::new();
let _ = jpg_hedge_hogs.load_file("qa_data/jpg/hedgehogs.jpg");

// The body of the POST request contains JSON that specifies the email subject, body,
// recipients, etc.  This example will build the following JSON HTML email:
// 

// 	{
// 	  "message": {
// 	    "subject": "Sample HTML Email with Embedded Images",
// 	    "body": {
// 	      "contentType": "html",
// 	      "content": "The HTML body goes here..."
// 	    },
// 	    "toRecipients": [
// 	      {
// 	        "emailAddress": {
// 		  "name": "Chilkat Software",
// 	          "address": "admin@chilkat.io"
// 	        }
// 	      },
// 	      {
// 	        "emailAddress": {
// 	          "address": "chilkat.support@gmail.com"
// 	        }
// 	      }
// 	    ],
// 	    "ccRecipients": [
// 	      {
// 	        "emailAddress": {
// 		  "name": "Chilkat Blog",
// 		  "address": "admin@cknotes.com"
// 	        }
// 	      }
// 	    ],
// 	    "attachments": [
// 	       {
// 	         "@odata.type": "#microsoft.graph.fileAttachment",
// 	         "name": "starfish.jpg",
// 	         "contentType": "image/jpeg",
// 	         "size": 6497,
// 	         "isInline": true,
// 	         "contentId": "starfish",
// 	         "contentLocation": null,
// 	         "contentBytes": "base64_data_here"
// 	       },
// 	       {
// 	         "@odata.type": "#microsoft.graph.fileAttachment",
// 	         "name": "hedgehogs.jpg",
// 	         "contentType": "image/jpeg",
// 	         "size": 48845,
// 	         "isInline": true,
// 	         "contentId": "hedgehogs",
// 	         "contentLocation": null,
// 	         "contentBytes": "base64_data_here"
// 	       }
// 	    ]
// 	  },
// 	  "saveToSentItems": true
// 	}
// 
// Build the above JSON.
let json = chilkat::JsonObject::new();
let _ = json.update_string("message.subject", "Sample HTML Email with Embedded Images");
let _ = json.update_string("message.body.contentType", "html");
let _ = json.update_string("message.body.content", &sb_html_body.get_as_string().unwrap_or_default());

let _ = json.update_string("message.toRecipients[0].emailAddress.name", "Chilkat Software");
let _ = json.update_string("message.toRecipients[0].emailAddress.address", "admin@chilkat.io");
let _ = json.update_string("message.toRecipients[1].emailAddress.address", "chilkat.support@gmail.com");
let _ = json.update_string("message.ccRecipients[0].emailAddress.name", "Chilkat Blog");
let _ = json.update_string("message.ccRecipients[0].emailAddress.address", "admin@cknotes.com");

let _ = json.update_string("message.attachments[0].\"@odata.type\"", "#microsoft.graph.fileAttachment");
let _ = json.update_string("message.attachments[0].name", "starfish.jpg");
let _ = json.update_string("message.attachments[0].contentType", "image/jpeg");
let _ = json.update_int("message.attachments[0].size", jpg_starfish.num_bytes());
let _ = json.update_bool("message.attachments[0].isInline", true);
// This contentId must match the "cid:" in the HTML
let _ = json.update_string("message.attachments[0].contentId", "starfish");
let _ = json.update_null("message.attachments[0].contentLocation");
let _ = json.update_bd("message.attachments[0].contentBytes", "base64", &jpg_starfish);

let _ = json.update_string("message.attachments[1].\"@odata.type\"", "#microsoft.graph.fileAttachment");
let _ = json.update_string("message.attachments[1].name", "hedgehogs.jpg");
let _ = json.update_string("message.attachments[1].contentType", "image/jpeg");
let _ = json.update_int("message.attachments[1].size", jpg_hedge_hogs.num_bytes());
let _ = json.update_bool("message.attachments[1].isInline", true);
// This contentId must match the "cid:" in the HTML
let _ = json.update_string("message.attachments[1].contentId", "hedgehogs");
let _ = json.update_null("message.attachments[1].contentLocation");
let _ = json.update_bd("message.attachments[1].contentBytes", "base64", &jpg_hedge_hogs);

let _ = json.update_bool("saveToSentItems", true);

// -------------------------------------------------------------
// Important: This example requires Chilkat v9.5.0.68 or greater.
// -------------------------------------------------------------

// Send the HTTP POST (i.e. send the HTML email)
let resp = chilkat::HttpResponse::new();
if http.http_json("POST", "https://graph.microsoft.com/v1.0/me/sendMail", &json, "application/json", &resp).is_err() {
    println!("{}", http.last_error_text());
    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.status_code() != 202 {
    let _ = json.load(&resp.body_str());
    json.set_emit_compact(false);
    println!("{}", json.emit().unwrap_or_default());
    println!("Failed, response status code = {}", resp.status_code());
} else {
    println!("Outlook HTML Mail Sent.");
}