diff --git a/.devenv/state/minio/data/.minio.sys/tmp/7b08971e-4836-4772-8f90-aa29588a6ef2 b/.devenv/state/minio/data/.minio.sys/tmp/7b08971e-4836-4772-8f90-aa29588a6ef2
new file mode 100644
index 00000000..e36ee446
Binary files /dev/null and b/.devenv/state/minio/data/.minio.sys/tmp/7b08971e-4836-4772-8f90-aa29588a6ef2 differ
diff --git a/apps/smtp-server/package.json b/apps/smtp-server/package.json
index da662c8a..4f911855 100644
--- a/apps/smtp-server/package.json
+++ b/apps/smtp-server/package.json
@@ -15,11 +15,14 @@
     "@types/mailparser": "^3.4.5",
     "@types/smtp-server": "^3.5.10",
     "dotenv": "^16.5.0",
+    "he": "^1.2.0",
+    "linkedom": "^0.18.12",
     "mailparser": "^3.7.2",
     "nodemailer": "^6.10.1",
     "smtp-server": "^3.13.6"
   },
   "devDependencies": {
+    "@types/he": "^1.2.3",
     "@types/node": "^22.15.2",
     "@types/nodemailer": "^6.4.17",
     "tsup": "^8.4.0",
diff --git a/apps/smtp-server/src/server.ts b/apps/smtp-server/src/server.ts
index 2a83c983..0eacab23 100644
--- a/apps/smtp-server/src/server.ts
+++ b/apps/smtp-server/src/server.ts
@@ -3,6 +3,8 @@ import { Readable } from "stream";
 import dotenv from "dotenv";
 import { simpleParser } from "mailparser";
 import { readFileSync, watch, FSWatcher } from "fs";
+import he from "he";
+import { parseHTML } from "linkedom";
 
 dotenv.config();
 
@@ -15,12 +17,128 @@ const SSL_KEY_PATH =
   process.env.USESEND_API_KEY_PATH ?? process.env.UNSEND_API_KEY_PATH;
 const SSL_CERT_PATH =
   process.env.USESEND_API_CERT_PATH ?? process.env.UNSEND_API_CERT_PATH;
+const CAMPAIGN_DOMAIN = process.env.USESEND_CAMPAIGN_DOMAIN ?? "usesend.com";
 
+interface ParsedRecipients {
+  contactBookIds: string[];
+  emailAddresses: string[];
+}
+
+/**
+ * Parses all recipients from the "to" field.
+ * - Addresses like "listId@usesend.com" (or configured domain) are contact book IDs
+ * - All other addresses are treated as individual email recipients
+ */
+function parseRecipients(to: string | undefined): ParsedRecipients {
+  const result: ParsedRecipients = {
+    contactBookIds: [],
+    emailAddresses: [],
+  };
+
+  if (!to) return result;
+
+  const emailRegex = /<?([^<>\s,]+@[^<>\s,]+)>?/g;
+  let match;
+
+  while ((match = emailRegex.exec(to)) !== null) {
+    const email = match[1].toLowerCase();
+    const [localPart, domain] = email.split("@");
+
+    if (domain === CAMPAIGN_DOMAIN.toLowerCase() && localPart) {
+      result.contactBookIds.push(localPart);
+    } else {
+      result.emailAddresses.push(email);
+    }
+  }
+
+  return result;
+}
+
+interface CampaignData {
+  name: string;
+  from: string;
+  subject: string;
+  contactBookId: string;
+  html: string;
+  replyTo?: string;
+}
+
+interface CampaignResponse {
+  id: string;
+  name: string;
+  status: string;
+}
+
+/**
+ * Creates a campaign and schedules it for immediate sending via the UseSend API.
+ */
+async function sendCampaignToUseSend(
+  campaignData: CampaignData,
+  apiKey: string,
+): Promise<CampaignResponse> {
+  try {
+    const createEndpoint = "/api/v1/campaigns";
+    const createUrl = new URL(createEndpoint, BASE_URL);
+
+    const payload = {
+      name: campaignData.name,
+      from: campaignData.from,
+      subject: campaignData.subject,
+      contactBookId: campaignData.contactBookId,
+      html: campaignData.html,
+      replyTo: campaignData.replyTo,
+      sendNow: true,
+    };
+
+    const response = await fetch(createUrl.href, {
+      method: "POST",
+      headers: {
+        Authorization: `Bearer ${apiKey}`,
+        "Content-Type": "application/json",
+      },
+      body: JSON.stringify(payload),
+    });
+
+    if (!response.ok) {
+      const errorText = await response.text();
+      let errorDisplay: string;
+      try {
+        // Try to parse and pretty-print JSON error responses
+        errorDisplay = JSON.stringify(JSON.parse(errorText), null, 2);
+      } catch {
+        errorDisplay = errorText;
+      }
+      console.error("useSend Campaign API error response:", errorDisplay);
+      throw new Error(
+        `Failed to create campaign: ${errorText || "Unknown error from server"}`,
+      );
+    }
+
+    const responseData = (await response.json()) as CampaignResponse;
+    return responseData;
+  } catch (error) {
+    if (error instanceof Error) {
+      console.error("Campaign error message:", error.message);
+      throw new Error(`Failed to send campaign: ${error.message}`);
+    } else {
+      console.error("Unexpected campaign error:", error);
+      throw new Error("Failed to send campaign: Unexpected error occurred");
+    }
+  }
+}
+
+/**
+ * Sends an individual email via the UseSend API.
+ *
+ * @param emailData - The email data object containing to, from, subject, text, html, and replyTo
+ * @param apiKey - The API key for authentication
+ * @throws Error if the API request fails
+ */
 async function sendEmailToUseSend(emailData: any, apiKey: string) {
   try {
     const apiEndpoint = "/api/v1/emails";
-    const url = new URL(apiEndpoint, BASE_URL); // Combine base URL with endpoint
-    console.log("Sending email to useSend API at:", url.href); // Debug statement
+    const url = new URL(apiEndpoint, BASE_URL);
+    console.log("Sending email to useSend API at:", url.href);
 
     const emailDataText = JSON.stringify(emailData);
 
@@ -34,14 +152,21 @@ async function sendEmailToUseSend(emailData: any, apiKey: string) {
     });
 
     if (!response.ok) {
-      const errorData = await response.text();
+      const errorText = await response.text();
+      let errorDisplay: string;
+      try {
+        // Try to parse and pretty-print JSON error responses
+        errorDisplay = JSON.stringify(JSON.parse(errorText), null, 2);
+      } catch {
+        errorDisplay = errorText;
+      }
       console.error(
-        "useSend API error response: error:",
-        JSON.stringify(errorData, null, 4),
+        "useSend API error response:",
+        errorDisplay,
         `\nemail data: ${emailDataText}`,
       );
       throw new Error(
-        `Failed to send email: ${errorData || "Unknown error from server"}`,
+        `Failed to send email: ${errorText || "Unknown error from server"}`,
       );
     }
 
@@ -58,6 +183,120 @@ async function sendEmailToUseSend(emailData: any, apiKey: string) {
   }
 }
 
+/**
+ * Converts plain text to a basic HTML document.
+ *
+ * Escapes HTML entities using the `he` library and converts newlines to `<br>` tags.
+ * Wraps the result in a minimal HTML document structure.
+ *
+ * @param text - The plain text content to convert
+ * @returns A complete HTML document string with the text as body content
+ */
+function textToHtml(text: string): string {
+  const escapedText = he.encode(text, { useNamedReferences: true });
+  // Convert newlines to <br> tags
+  const htmlText = escapedText.replace(/\n/g, "<br>\n");
+  return `<!DOCTYPE html><html><body><p>${htmlText}</p></body></html>`;
+}
+
+/**
+ * Creates an unsubscribe footer element for campaign emails.
+ *
+ * Generates a styled paragraph containing an unsubscribe link with the
+ * `{{usesend_unsubscribe_url}}` placeholder, which will be replaced with
+ * the actual unsubscribe URL when the campaign is sent.
+ *
+ * @param document - The DOM Document to create elements in
+ * @returns An HTMLElement containing the styled unsubscribe link
+ */
+function createUnsubscribeFooter(document: Document): HTMLElement {
+  const footer = document.createElement("p");
+  footer.setAttribute(
+    "style",
+    "margin-top: 20px; padding-top: 20px; border-top: 1px solid #eee; font-size: 12px; color: #666;",
+  );
+
+  const link = document.createElement("a");
+  link.setAttribute("href", "{{usesend_unsubscribe_url}}");
+  link.setAttribute("style", "color: #666;");
+  link.textContent = "Unsubscribe";
+
+  footer.appendChild(link);
+  return footer;
+}
+
+/**
+ * Checks if the HTML content already contains an unsubscribe link placeholder.
+ *
+ * Looks for both legacy `{{unsend_unsubscribe_url}}` and current
+ * `{{usesend_unsubscribe_url}}` placeholders.
+ *
+ * @param html - The HTML content to check
+ * @returns True if an unsubscribe placeholder is found, false otherwise
+ */
+function hasUnsubscribeLink(html: string): boolean {
+  return (
+    html.includes("{{unsend_unsubscribe_url}}") ||
+    html.includes("{{usesend_unsubscribe_url}}")
+  );
+}
+
+/**
+ * Prepares HTML content for campaign sending.
+ *
+ * This function ensures the email content is ready for campaign delivery by:
+ * 1. Converting plain text to HTML if no HTML content is provided
+ * 2. Adding an unsubscribe footer if one doesn't already exist
+ *
+ * Uses linkedom for proper DOM manipulation rather than string replacement,
+ * ensuring robust handling of various HTML structures.
+ *
+ * @param html - The HTML content from the email, or false/undefined if not provided
+ * @param text - The plain text content from the email, used as fallback
+ * @returns The prepared HTML string, or null if no content is available
+ */
+function prepareCampaignHtml(
+  html: string | false | undefined,
+  text: string | undefined,
+): string | null {
+  // Convert plain text to HTML if no HTML provided
+  let htmlContent: string;
+  if (!html && text) {
+    htmlContent = textToHtml(text);
+  } else if (html) {
+    htmlContent = html;
+  } else {
+    return null;
+  }
+
+  // Check if unsubscribe link already exists
+  if (hasUnsubscribeLink(htmlContent)) {
+    return htmlContent;
+  }
+
+  // Parse the HTML and add the unsubscribe footer using DOM APIs
+  const { document } = parseHTML(htmlContent);
+
+  const footer = createUnsubscribeFooter(document);
+
+  // Append to body if it exists, otherwise append to document
+  const body = document.querySelector("body");
+  if (body) {
+    body.appendChild(footer);
+  } else {
+    // No body tag - wrap content and add footer
+    const html = document.querySelector("html");
+    if (html) {
+      html.appendChild(footer);
+    } else {
+      // Minimal HTML - just append
+      document.appendChild(footer);
+    }
+  }
+
+  return document.toString();
+}
+
 function loadCertificates(): { key?: Buffer; cert?: Buffer } {
   return {
     key: SSL_KEY_PATH ? readFileSync(SSL_KEY_PATH) : undefined,
@@ -77,7 +316,7 @@ const serverOptions: SMTPServerOptions = {
     callback: (error?: Error) => void,
   ) {
     console.log("Receiving email data..."); // Debug statement
-    simpleParser(stream, (err, parsed) => {
+    simpleParser(stream, async (err, parsed) => {
       if (err) {
         console.error("Failed to parse email data:", err.message);
         return callback(err);
@@ -88,26 +327,102 @@ const serverOptions: SMTPServerOptions = {
         return callback(new Error("No API key found in session"));
       }
 
-      const emailObject = {
-        to: Array.isArray(parsed.to)
-          ? parsed.to.map((addr) => addr.text).join(", ")
-          : parsed.to?.text,
-        from: Array.isArray(parsed.from)
-          ? parsed.from.map((addr) => addr.text).join(", ")
-          : parsed.from?.text,
-        subject: parsed.subject,
-        text: parsed.text,
-        html: parsed.html,
-        replyTo: parsed.replyTo?.text,
-      };
-
-      sendEmailToUseSend(emailObject, session.user)
-        .then(() => callback())
-        .then(() => console.log("Email sent successfully to: ", emailObject.to))
-        .catch((error) => {
-          console.error("Failed to send email:", error.message);
-          callback(error);
+      const toAddress = Array.isArray(parsed.to)
+        ? parsed.to.map((addr) => addr.text).join(", ")
+        : parsed.to?.text;
+
+      const fromAddress = Array.isArray(parsed.from)
+        ? parsed.from.map((addr) => addr.text).join(", ")
+        : parsed.from?.text;
+
+      const sendPromises: Promise<any>[] = [];
+      const recipients = parseRecipients(toAddress);
+      const hasCampaigns = recipients.contactBookIds.length > 0;
+      const hasIndividualEmails = recipients.emailAddresses.length > 0;
+
+      // Handle campaign sends (one campaign per contact book)
+      if (hasCampaigns) {
+        if (!fromAddress) {
+          console.error("No from address found for campaign");
+          return callback(new Error("From address is required for campaigns"));
+        }
+
+        if (!parsed.subject) {
+          console.error("No subject found for campaign");
+          return callback(new Error("Subject is required for campaigns"));
+        }
+
+        const htmlContent = prepareCampaignHtml(parsed.html, parsed.text);
+        if (!htmlContent) {
+          console.error("No content found for campaign");
+          return callback(
+            new Error("HTML or text content is required for campaigns"),
+          );
+        }
+
+        for (const contactBookId of recipients.contactBookIds) {
+          const campaignData: CampaignData = {
+            name: `SMTP Campaign: ${parsed.subject}`,
+            from: fromAddress,
+            subject: parsed.subject,
+            contactBookId,
+            html: htmlContent,
+            replyTo: parsed.replyTo?.text,
+          };
+
+          const campaignPromise = sendCampaignToUseSend(
+            campaignData,
+            session.user,
+          ).catch((error) => {
+            console.error(
+              `Failed to send campaign to ${contactBookId}:`,
+              error.message,
+            );
+            throw error;
+          });
+
+          sendPromises.push(campaignPromise);
+        }
+      }
+
+      // Handle individual email sends
+      if (hasIndividualEmails) {
+        // Send to all individual recipients in one API call
+        const emailObject = {
+          to: recipients.emailAddresses,
+          from: fromAddress,
+          subject: parsed.subject,
+          text: parsed.text,
+          html: parsed.html,
+          replyTo: parsed.replyTo?.text,
+        };
+
+        const emailPromise = sendEmailToUseSend(
+          emailObject,
+          session.user,
+        ).catch((error) => {
+          console.error("Failed to send individual emails:", error.message);
+          throw error;
         });
+
+        sendPromises.push(emailPromise);
+      }
+
+      if (sendPromises.length === 0) {
+        console.error("No valid recipients found");
+        return callback(new Error("No valid recipients found"));
+      }
+
+      try {
+        await Promise.all(sendPromises);
+        callback();
+      } catch (error) {
+        if (error instanceof Error) {
+          callback(error);
+        } else {
+          callback(new Error("One or more sends failed"));
+        }
+      }
     });
   },
   onAuth(auth, session: any, callback: (error?: Error, user?: any) => void) {
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 88867c2a..48b1de47 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -127,6 +127,12 @@ importers:
       dotenv:
         specifier: ^16.5.0
         version: 16.5.0
+      he:
+        specifier: ^1.2.0
+        version: 1.2.0
+      linkedom:
+        specifier: ^0.18.12
+        version: 0.18.12
       mailparser:
         specifier: ^3.7.2
         version: 3.7.2
@@ -137,6 +143,9 @@ importers:
         specifier: ^3.13.6
         version: 3.13.6
     devDependencies:
+      '@types/he':
+        specifier: ^1.2.3
+        version: 1.2.3
       '@types/node':
         specifier: ^22.15.2
         version: 22.15.2
@@ -8224,6 +8233,10 @@ packages:
     dependencies:
       '@types/unist': 3.0.3
 
+  /@types/he@1.2.3:
+    resolution: {integrity: sha512-q67/qwlxblDzEDvzHhVkwc1gzVWxaNxeyHUBF4xElrvjL11O+Ytze+1fGpBHlr/H9myiBUaUXNnNPmBHxxfAcA==}
+    dev: true
+
   /@types/html-to-text@9.0.4:
     resolution: {integrity: sha512-pUY3cKH/Nm2yYrEmDlPR1mR7yszjGx4DrwPjQ702C4/D5CwHuZTgZdIdwPkRbcuhs7BAh2L5rg3CL5cbRiGTCQ==}
     dev: true
@@ -10066,6 +10079,16 @@ packages:
       shebang-command: 2.0.0
       which: 2.0.2
 
+  /css-select@5.2.2:
+    resolution: {integrity: sha512-TizTzUddG/xYLA3NXodFM0fSbNizXjOKhqiQQwvhlspadZokn1KDy0NZFS0wuEubIYAV5/c1/lAr0TaaFXEXzw==}
+    dependencies:
+      boolbase: 1.0.0
+      css-what: 6.1.0
+      domhandler: 5.0.3
+      domutils: 3.2.2
+      nth-check: 2.1.1
+    dev: false
+
   /css-selector-parser@3.1.3:
     resolution: {integrity: sha512-gJMigczVZqYAk0hPVzx/M4Hm1D9QOtqkdQk9005TNzDIUGzo5cnHEDiKUT7jGPximL/oYb+LIitcHFQ4aKupxg==}
     dev: false
@@ -10080,6 +10103,10 @@ packages:
     engines: {node: '>=4'}
     hasBin: true
 
+  /cssom@0.5.0:
+    resolution: {integrity: sha512-iKuQcq+NdHqlAcwUY0o/HL69XQrUaQdMjmStJ8JFmUaiiQErlhrmuigkg/CU4E2J0IyUKUrMAgl36TvN67MqTw==}
+    dev: false
+
   /csstype@3.1.3:
     resolution: {integrity: sha512-M1uQkMl8rQK/szD0LNhtqxIPLpimGm8sOBwU7lLnCpSbTyY3yeU1Vc7l4KT5zT4s/yOxHH5O7tIuuLOCnLADRw==}
 
@@ -12426,6 +12453,10 @@ packages:
     resolution: {integrity: sha512-fxfswuADQ6N6RmCUYoCEIw09Zbk/h8GJSJsbiQ3Uw3mkQegJ5b7Eu5Tpxl2xDUq9meWmivHe0GFieG2qHl2j4A==}
     dev: false
 
+  /html-escaper@3.0.3:
+    resolution: {integrity: sha512-RuMffC89BOWQoY0WKGpIhn5gX3iI54O6nRA0yC124NYVtzjmFWBIiFd8M0x+ZdX0P9R4lADg1mgP8C7PxGOWuQ==}
+    dev: false
+
   /html-to-text@9.0.5:
     resolution: {integrity: sha512-qY60FjREgVZL03vJU6IfMV4GDjGBIoOyvuFdpBDIX9yTlDw0TjxVBQp+P8NvpdIXNJvfWBTNul7fsAQJq2FNpg==}
     engines: {node: '>=14'}
@@ -12440,6 +12471,15 @@ packages:
   /html-void-elements@3.0.0:
     resolution: {integrity: sha512-bEqo66MRXsUGxWHV5IP0PUiAWwoEjba4VCzg0LjFJBpchPaTfyfCKTG6bc5F8ucKec3q5y6qOdGyYTSBEvhCrg==}
 
+  /htmlparser2@10.0.0:
+    resolution: {integrity: sha512-TwAZM+zE5Tq3lrEHvOlvwgj1XLWQCtaaibSN11Q+gGBAS7Y1uZSWwXXRe4iF6OXnaq1riyQAPFOBtYc77Mxq0g==}
+    dependencies:
+      domelementtype: 2.3.0
+      domhandler: 5.0.3
+      domutils: 3.2.2
+      entities: 6.0.0
+    dev: false
+
   /htmlparser2@8.0.2:
     resolution: {integrity: sha512-GYdjWKDkbRLkZ5geuHs5NY1puJ+PXwP7+fHPRz06Eirsb9ugf6d8kkXav6ADhcODhFFPMIXyxkxSuMf3D6NCFA==}
     dependencies:
@@ -13364,6 +13404,22 @@ packages:
   /lines-and-columns@1.2.4:
     resolution: {integrity: sha512-7ylylesZQ/PV29jhEDl3Ufjo6ZX7gCqJr5F7PKrqc93v7fzSymt1BpwEU8nAUXs8qzzvqhbjhK5QZg6Mt/HkBg==}
 
+  /linkedom@0.18.12:
+    resolution: {integrity: sha512-jalJsOwIKuQJSeTvsgzPe9iJzyfVaEJiEXl+25EkKevsULHvMJzpNqwvj1jOESWdmgKDiXObyjOYwlUqG7wo1Q==}
+    engines: {node: '>=16'}
+    peerDependencies:
+      canvas: '>= 2'
+    peerDependenciesMeta:
+      canvas:
+        optional: true
+    dependencies:
+      css-select: 5.2.2
+      cssom: 0.5.0
+      html-escaper: 3.0.3
+      htmlparser2: 10.0.0
+      uhyphen: 0.2.0
+    dev: false
+
   /linkify-it@5.0.0:
     resolution: {integrity: sha512-5aHCbzQRADcdP+ATqnDuhhJ/MRIqDkZX5pyjFHRRysS8vZ5AbqGEoFIb6pYHPZ+L/OC2Lc+xT8uHVVR5CAK/wQ==}
     dependencies:
@@ -18027,6 +18083,10 @@ packages:
     resolution: {integrity: sha512-ARDJmphmdvUk6Glw7y9DQ2bFkKBHwQHLi2lsaH6PPmz/Ka9sFOBsBluozhDltWmnv9u/cF6Rt87znRTPV+yp/A==}
     dev: false
 
+  /uhyphen@0.2.0:
+    resolution: {integrity: sha512-qz3o9CHXmJJPGBdqzab7qAYuW8kQGKNEuoHFYrBwV6hWIMcpAmxDLXojcHfFr9US1Pe6zUswEIJIbLI610fuqA==}
+    dev: false
+
   /unbox-primitive@1.1.0:
     resolution: {integrity: sha512-nWJ91DjeOkej/TA8pXQ3myruKpKEYgqvpw9lz4OPHj/NWFNluYrjbz9j01CJ8yKQd2g4jFoOkINCTW2I5LEEyw==}
     engines: {node: '>= 0.4'}
diff --git a/temp b/temp
new file mode 100644
index 00000000..e69de29b