1 files changed, 73 insertions, 3 deletions

diff --git a/deno/mail/mail.ts b/deno/mail/mail.ts
index 9cc591c..b88ce2b 100644
--- a/deno/mail/mail.ts
+++ b/deno/mail/mail.ts
@@ -1,5 +1,8 @@
 import { encodeBase64 } from "@std/encoding/base64";
 import { parse } from "@std/csv/parse";
+
+import { StringUtils } from "@crupest/base";
+
 import { simpleParseMail } from "./mail-parsing.ts";
 
 export class Mail {
@@ -47,7 +50,9 @@ export interface MailDeliverRecipientResult {
 
 export class MailDeliverResult {
   message?: string;
-  smtpMessage?: string;
+  messageForSmtp?: string;
+  newMessageId?: string;
+
   recipients = new Map<string, MailDeliverRecipientResult>();
   constructor(public mail: Mail) {}
 
@@ -58,8 +63,8 @@ export class MailDeliverResult {
   generateLogMessage(prefix: string) {
     const lines = [];
     if (this.message != null) lines.push(`${prefix} message: ${this.message}`);
-    if (this.smtpMessage != null) {
-      lines.push(`${prefix} smtpMessage: ${this.smtpMessage}`);
+    if (this.messageForSmtp != null) {
+      lines.push(`${prefix} smtpMessage: ${this.messageForSmtp}`);
     }
     for (const [name, result] of this.recipients.entries()) {
       const { kind, message } = result;
@@ -67,6 +72,13 @@ export class MailDeliverResult {
     }
     return lines.join("\n");
   }
+
+  generateMessageForSmtp(): string {
+    if (this.messageForSmtp != null) return this.messageForSmtp;
+    return `2.0.0 OK${
+      StringUtils.prependNonEmpty(this.newMessageId)
+    } Message accepted for delivery`;
+  }
 }
 
 export class MailDeliverContext {
@@ -232,3 +244,61 @@ export class AliasRecipientMailHook implements MailDeliverHook {
     }
   }
 }
+
+export class MessageIdRewriteHook implements MailDeliverHook {
+  readonly #lookup;
+
+  constructor(lookup: (origin: string) => Promise<string | null>) {
+    this.#lookup = lookup;
+  }
+
+  async callback(context: MailDeliverContext): Promise<void> {
+    const addresses = context.mail.simpleFindAllAddresses();
+    for (const address of addresses) {
+      const newMessageId = await this.#lookup(address);
+      if (newMessageId != null && newMessageId.length !== 0) {
+        console.info(
+          context.logTag,
+          `Rewrite address-line string in mail: ${address} => ${newMessageId}.`,
+        );
+        context.mail.raw = context.mail.raw.replaceAll(address, newMessageId);
+      }
+    }
+  }
+}
+
+export class MessageIdSaveHook implements MailDeliverHook {
+  readonly #record;
+
+  constructor(
+    record: (
+      original: string,
+      newMessageId: string,
+      context: MailDeliverContext,
+    ) => Promise<void>,
+  ) {
+    this.#record = record;
+  }
+
+  async callback(context: MailDeliverContext): Promise<void> {
+    const { messageId } = context.mail.parsed;
+    if (messageId == null) {
+      console.warn(
+        context.logTag,
+        "Original mail doesn't have message id, skip saving message id map.",
+      );
+      return;
+    }
+    if (context.result.newMessageId != null) {
+      console.info(
+        context.logTag,
+        `Save message id map: ${messageId} => ${context.result.newMessageId}.`,
+      );
+      context.mail.raw = context.mail.raw.replaceAll(
+        messageId,
+        context.result.newMessageId,
+      );
+      await this.#record(messageId, context.result.newMessageId, context);
+    }
+  }
+}