feat: add notification provider SendGrid (#5205)

Co-authored-by: Frank Elsinga <frank@elsinga.de>

server/notification-providers/send-grid.js

@@ -0,0 +1,65 @@
+const NotificationProvider = require("./notification-provider");
+const axios = require("axios");
+
+class SendGrid extends NotificationProvider {
+    name = "SendGrid";
+
+    /**
+     * @inheritdoc
+     */
+    async send(notification, msg, monitorJSON = null, heartbeatJSON = null) {
+        const okMsg = "Sent Successfully.";
+
+        try {
+            let config = {
+                headers: {
+                    "Content-Type": "application/json",
+                    Authorization: `Bearer ${notification.sendgridApiKey}`,
+                },
+            };
+
+            let personalizations = {
+                to: [{ email: notification.sendgridToEmail }],
+            };
+
+            // Add CC recipients if provided
+            if (notification.sendgridCcEmail) {
+                personalizations.cc = notification.sendgridCcEmail
+                    .split(",")
+                    .map((email) => ({ email: email.trim() }));
+            }
+
+            // Add BCC recipients if provided
+            if (notification.sendgridBccEmail) {
+                personalizations.bcc = notification.sendgridBccEmail
+                    .split(",")
+                    .map((email) => ({ email: email.trim() }));
+            }
+
+            let data = {
+                personalizations: [ personalizations ],
+                from: { email: notification.sendgridFromEmail.trim() },
+                subject:
+          notification.sendgridSubject ||
+          "Notification from Your Uptime Kuma",
+                content: [
+                    {
+                        type: "text/plain",
+                        value: msg,
+                    },
+                ],
+            };
+
+            await axios.post(
+                "https://api.sendgrid.com/v3/mail/send",
+                data,
+                config
+            );
+            return okMsg;
+        } catch (error) {
+            this.throwGeneralAxiosError(error);
+        }
+    }
+}
+
+module.exports = SendGrid;