Decode QOutlook legacy MIME words

src/io/outlookMail.test.ts

@@ -37,6 +37,9 @@ describe("outlookMail helpers", () => {
 
   it("декодирует UTF-8 MIME words и transfer encodings", () => {
     expect(decodeMimeWords("=?UTF-8?B?0J/RgNC40LLQtdGC?=")).toBe("Привет");
+    expect(decodeMimeWords("=?windows-1251?B?z/Do4uXy?=")).toBe("Привет");
+    expect(decodeMimeWords("=?windows-1251?Q?=CF=F0=E8=E2=E5=F2?=")).toBe("Привет");
+    expect(decodeMimeWords("=?UTF-8?B?0J/RgNC4?= =?UTF-8?B?0LLQtdGC?=")).toBe("Привет");
     expect(decodeTransferBody("0J/RgNC40LLQtdGC", "base64")).toBe("Привет");
     expect(decodeTransferBody("=D0=9F=D1=80=D0=B8=D0=B2=D0=B5=D1=82", "quoted-printable")).toBe("Привет");
   });

src/io/outlookMail.ts

@@ -457,18 +457,13 @@ function optionalAddressHeaders(message: MailMessage): string[] {
 }
 
 export function decodeMimeWords(value: string): string {
-  return value.replace(/=\?([^?]+)\?([bqBQ])\?([^?]+)\?=/g, (_match, charset: string, encoding: string, encoded: string) => {
-    const normalizedCharset = charset.toLowerCase();
-    if (normalizedCharset !== "utf-8" && normalizedCharset !== "utf8") {
-      return _match;
-    }
-
-    if (encoding.toLowerCase() === "b") {
-      return decodeUtf8Bytes(base64ToBytes(encoded));
-    }
-
-    return decodeUtf8Bytes(quotedPrintableToBytes(encoded.replace(/_/g, " ")));
-  });
+  return value
+    .replace(/(=\?[^?]+\?[bqBQ]\?[^?]+\?=)\s+(?==\?[^?]+\?[bqBQ]\?[^?]+\?=)/g, "$1")
+    .replace(/=\?([^?]+)\?([bqBQ])\?([^?]+)\?=/g, (match, charset: string, encoding: string, encoded: string) => {
+      const bytes = encoding.toLowerCase() === "b" ? base64ToBytes(encoded) : quotedPrintableToBytes(encoded.replace(/_/g, " "));
+      const decoded = decodeBytes(bytes, charset);
+      return decoded || match;
+    });
 }
 
 export function decodeTransferBody(body: string, encoding = "", charset = "utf-8"): string {