Fix unsubscription email address.

Change-Id: Iac6491ead60a969e38634c72fdec29f00890c2ce
diff --git a/src/main/resources/templates/NewsletterResource/registered.html b/src/main/resources/templates/NewsletterResource/registered.html
index e82618e..9e0062f 100644
--- a/src/main/resources/templates/NewsletterResource/registered.html
+++ b/src/main/resources/templates/NewsletterResource/registered.html
@@ -18,7 +18,7 @@
     <p>Thank you. You are now subscribed to the weekly email digest.</p>
 
     <p>To unsubscribe, send an email to
-      <a href="mailto:mulkcms+unsubscribe@benkard.de">mulkcms+unsubscribe@benkard.de</a>.</p>
+      <a href="mailto:mulkcms+unsubscribe@mail.benkard.de">mulkcms+unsubscribe@mail.benkard.de</a>.</p>
   </section>
 </article>
 {/body}