diff --git a/packages/helpers/src/dkim/index.ts b/packages/helpers/src/dkim/index.ts
index d3350589b..d3bc6ab28 100644
--- a/packages/helpers/src/dkim/index.ts
+++ b/packages/helpers/src/dkim/index.ts
@@ -20,6 +20,20 @@ export async function verifyDKIMSignature(
   domain: string = "",
   tryRevertARCChanges: boolean = true
 ): Promise<DKIMVerificationResult> {
+
+  const emailStr = email.toString();
+
+  const pgpMarkers = [
+    "BEGIN PGP MESSAGE",
+    "BEGIN PGP SIGNED MESSAGE",
+    "X-Pm-Content-Encryption: end-to-end",
+  ];
+
+  const isPGPEncoded = pgpMarkers.some(marker => emailStr.includes(marker));
+
+  if (isPGPEncoded) {
+    throw new Error("PGP encoded emails are not supported.");
+  }
   let dkimResult = await tryVerifyDKIM(email, domain);
 
   if (dkimResult.status.result !== "pass" && tryRevertARCChanges) {