diff --git a/Lib/email/test/test_email.py b/Lib/email/test/test_email.py
index 5545abe..7993486 100644
--- a/Lib/email/test/test_email.py
+++ b/Lib/email/test/test_email.py
@@ -2457,6 +2457,10 @@
     text/rfc822-headers
 """)
 
+    def test_make_msgid_domain(self):
+        self.assertEqual(
+            email.utils.make_msgid(domain='testdomain-string')[-19:],
+            '@testdomain-string>')
 
 
 # Test the iterator/generators
diff --git a/Lib/email/utils.py b/Lib/email/utils.py
index 5f40bac..ac4da37 100644
--- a/Lib/email/utils.py
+++ b/Lib/email/utils.py
@@ -148,13 +148,15 @@
 
 
 
-def make_msgid(idstring=None):
+def make_msgid(idstring=None, domain=None):
     """Returns a string suitable for RFC 2822 compliant Message-ID, e.g:
 
     <20020201195627.33539.96671@nightshade.la.mastaler.com>
 
     Optional idstring if given is a string used to strengthen the
-    uniqueness of the message id.
+    uniqueness of the message id.  Optional domain if given provides the
+    portion of the message id after the '@'.  It defaults to the locally
+    defined hostname.
     """
     timeval = time.time()
     utcdate = time.strftime('%Y%m%d%H%M%S', time.gmtime(timeval))
@@ -164,8 +166,9 @@
         idstring = ''
     else:
         idstring = '.' + idstring
-    idhost = socket.getfqdn()
-    msgid = '<%s.%s.%s%s@%s>' % (utcdate, pid, randint, idstring, idhost)
+    if domain is None:
+        domain = socket.getfqdn()
+    msgid = '<%s.%s.%s%s@%s>' % (utcdate, pid, randint, idstring, domain)
     return msgid