Add support for email sending through Lettermint

Author: matteocontrini

.env.example

@@ -1,3 +1,5 @@
 WEBSITE_URL=http://localhost:5180
 DATABASE_URL="postgresql://postgres:@localhost:5432/certs-email?schema=public"
+EMAIL_PROVIDER=lettermint
+LETTERMINT_API_TOKEN=
 MAILTRAP_API_KEY=

package-lock.json

@@ -50,6 +50,7 @@
 		"handlebars": "^4.7.8",
 		"ipaddr.js": "^2.2.0",
 		"juice": "^11.1.0",
+		"lettermint": "^1.5.0",
 		"mailtrap": "^4.4.0",
 		"mode-watcher": "^1.1.0",
 		"pg": "^8.16.3",

package.json

@@ -1,33 +1,73 @@
 import { env } from '$env/dynamic/private';
 import { MailtrapClient } from 'mailtrap';
+import { Lettermint } from 'lettermint';
 import { building, dev } from '$app/environment';
 import type { EmailOutbox } from '$prisma/generated/client';
 
-if (!building && !env.MAILTRAP_API_KEY) throw new Error('MAILTRAP_API_KEY is not set');
+const provider = env.EMAIL_PROVIDER || 'lettermint';
 
-const mailtrap = new MailtrapClient({
-	token: env.MAILTRAP_API_KEY!
-});
+if (!building) {
+	if (provider === 'mailtrap' && !env.MAILTRAP_API_KEY) {
+		throw new Error('MAILTRAP_API_KEY is not set');
+	}
+	if (provider === 'lettermint' && !env.LETTERMINT_API_TOKEN) {
+		throw new Error('LETTERMINT_API_TOKEN is not set');
+	}
+}
+
+let mailtrap: MailtrapClient | undefined;
+let lettermint: Lettermint | undefined;
 
-const defaultFrom = { name: 'certs.email', email: 'support@certs.email' };
+function getMailtrap() {
+	if (!mailtrap) mailtrap = new MailtrapClient({ token: env.MAILTRAP_API_KEY! });
+	return mailtrap;
+}
+
+function getLettermint() {
+	if (!lettermint) lettermint = new Lettermint({ apiToken: env.LETTERMINT_API_TOKEN! });
+	return lettermint;
+}
+
+const defaultFrom = { name: 'certs.email', email: dev ? 'support@dev.certs.email' : 'support@certs.email' };
 
 export const EmailOutboxPriorities = {
 	High: 0,
 	Medium: 5,
 	Low: 10
 } as const;
 
+async function sendEmail(options: { to: string[]; subject: string; html: string; tag?: string }) {
+	if (provider === 'mailtrap') {
+		await getMailtrap().send({
+			from: defaultFrom,
+			to: options.to.map((email) => ({ email })),
+			subject: options.subject,
+			html: options.html,
+			category: options.tag
+		});
+	} else {
+		const email = getLettermint()
+			.email.from(`${defaultFrom.name} <${defaultFrom.email}>`)
+			.to(...options.to)
+			.subject(options.subject)
+			.html(options.html);
+
+		if (options.tag) email.tag(options.tag);
+
+		await email.send();
+	}
+}
+
 export async function sendQueuedEmail(job: EmailOutbox) {
-	let category = undefined;
+	let tag = undefined;
 	if (job.templateName) {
-		category = dev ? `DEV-CERTS-${job.templateName}` : `PROD-CERTS-${job.templateName}`;
+		tag = dev ? `DEV-CERTS-${job.templateName}` : `PROD-CERTS-${job.templateName}`;
 	}
 
-	await mailtrap.send({
-		from: defaultFrom,
-		to: job.recipients.map((email) => ({ email })),
+	await sendEmail({
+		to: job.recipients,
 		subject: job.subject,
 		html: job.body,
-		category
+		tag
 	});
 }