diff --git a/configuration.local.js b/configuration.local.js
index 4151754..1efcd1f 100644
--- a/configuration.local.js
+++ b/configuration.local.js
@@ -6,9 +6,7 @@ module.exports = (require) => {
     console.log(`Web server started at ${webApplication.get("url")}`);
   });
 
-  emailApplication.listen(webApplication.get("email port"), () => {
-    console.log(
-      `Email server started on port ${webApplication.get("email port")}`
-    );
+  emailApplication.listen(new URL(webApplication.get("email")).port, () => {
+    console.log(`Email server started at port ${webApplication.get("email")}`);
   });
 };
diff --git a/src/index.test.ts b/src/index.test.ts
index 8c063e1..4aa7fcb 100644
--- a/src/index.test.ts
+++ b/src/index.test.ts
@@ -1,8 +1,33 @@
-import { webServer, emailServer, BASE_URL, EMAIL_DOMAIN, EMAIL_PORT } from ".";
+import { beforeAll, afterAll, describe, test, expect } from "@jest/globals";
+import os from "os";
+import path from "path";
+import http from "http";
+import net from "net";
+import fs from "fs";
+import * as got from "got";
 import nodemailer from "nodemailer";
-import axios from "axios";
-import qs from "qs";
-import { JSDOM } from "jsdom";
+import killTheNewsletter from ".";
+
+let webServer: http.Server;
+let emailServer: net.Server;
+let webClient: got.Got;
+let emailClient: nodemailer.Transporter;
+beforeAll(() => {
+  const rootDirectory = fs.mkdtempSync(
+    path.join(os.tmpdir(), "kill-the-newsletter--test--")
+  );
+  const { webApplication, emailApplication } = killTheNewsletter(rootDirectory);
+  webServer = webApplication.listen(new URL(webApplication.get("url")).port);
+  emailServer = emailApplication.listen(
+    new URL(webApplication.get("email")).port
+  );
+  webClient = got.default.extend({ prefixUrl: webApplication.get("url") });
+  emailClient = nodemailer.createTransport(webApplication.get("email"));
+});
+afterAll(() => {
+  webServer.close();
+  emailServer.close();
+});
 
 test("create feed", async () => {
   const identifier = await createFeed();
@@ -235,12 +260,6 @@ test("‘noindex’ header", async () => {
   );
 });
 
-const webClient = axios.create({
-  baseURL: BASE_URL,
-});
-const emailClient = nodemailer.createTransport(
-  `smtp://${EMAIL_DOMAIN}:${EMAIL_PORT}`
-);
 afterAll(() => {
   webServer.close();
   emailServer.close();
diff --git a/src/index.ts b/src/index.ts
index faea50c..5fc37ac 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -20,8 +20,7 @@ export default function killTheNewsletter(
   const webApplication = express();
 
   webApplication.set("url", "http://localhost:4000");
-  webApplication.set("email port", 2525);
-  webApplication.set("email host", "localhost");
+  webApplication.set("email", "smtp://localhost:2525");
   webApplication.set("administrator", "mailto:kill-the-newsletter@leafac.com");
 
   fs.ensureDirSync(rootDirectory);
@@ -287,7 +286,8 @@ export default function killTheNewsletter(
       <p>
         Sign up for the newsletter with<br />
         <code class="copyable"
-          >${feedReference}@${webApplication.get("email host")}</code
+          >${feedReference}@${new URL(webApplication.get("email"))
+            .hostname}</code
         >
       </p>
       <p>
@@ -376,7 +376,7 @@ export default function killTheNewsletter(
         <title>${feed.title}</title>
         <subtitle
           >Kill the Newsletter! Inbox:
-          ${feedReference}@${webApplication.get("email host")} →
+          ${feedReference}@${new URL(webApplication.get("email")).hostname} →
           ${webApplication.get("url")}/feeds/${feedReference}.xml</subtitle
         >
         <updated>${new Date(feed.updatedAt).toISOString()}</updated>
@@ -443,7 +443,7 @@ export default function killTheNewsletter(
     disabledCommands: ["AUTH", "STARTTLS"],
     async onData(stream, session, callback) {
       try {
-        const atHost = "@" + webApplication.get("email host");
+        const atHost = "@" + new URL(webApplication.get("email")).hostname;
         const email = await mailparser.simpleParser(stream);
         const from = email.from?.text ?? "";
         const subject = email.subject ?? "";