diff --git a/emailtunnel/__init__.py b/emailtunnel/__init__.py
index b713772..a742b65 100644
--- a/emailtunnel/__init__.py
+++ b/emailtunnel/__init__.py
@@ -28,6 +28,7 @@
 import sys
 import logging
 import datetime
+import itertools
 
 import email
 import email.mime.multipart
@@ -42,6 +43,22 @@
 import smtplib
 
 
+def abbreviate_recipient_list(recipients):
+    if all('@' in rcpt for rcpt in recipients):
+        parts = [rcpt.split('@', 1) for rcpt in recipients]
+        parts.sort(key=lambda x: (x[1].lower(), x[0].lower()))
+        by_domain = [
+            (domain, [a[0] for a in aa])
+            for domain, aa in itertools.groupby(
+                parts, key=lambda x: x[1])
+        ]
+        return ', '.join(
+            '<%s@%s>' % (','.join(aa), domain)
+            for domain, aa in by_domain)
+    else:
+        return ', '.join('<%s>' % x for x in recipients)
+
+
 def _fix_eols(data):
     if isinstance(data, six.string_types):
         return re.sub(r'(?:\r\n|\n|\r)', "\r\n", data)
diff --git a/tkmail/server.py b/tkmail/server.py
index 12962e3..b067d1b 100644
--- a/tkmail/server.py
+++ b/tkmail/server.py
@@ -10,6 +10,7 @@
 
 import email.header
 
+import emailtunnel
 from emailtunnel import SMTPForwarder, Message
 
 import tkmail.address
@@ -90,19 +91,7 @@ def log_receipt(self, peer, envelope):
                      % (str(message.subject), sender, recipients))
 
     def log_delivery(self, message, recipients, sender):
-        if all('@' in rcpt for rcpt in recipients):
-            parts = [rcpt.split('@', 1) for rcpt in recipients]
-            parts.sort(key=lambda x: (x[1].lower(), x[0].lower()))
-            by_domain = [
-                (domain, [a[0] for a in aa])
-                for domain, aa in itertools.groupby(
-                    parts, key=lambda x: x[1])
-            ]
-            recipients_string = ', '.join(
-                '<%s@%s>' % (','.join(aa), domain)
-                for domain, aa in by_domain)
-        else:
-            recipients_string = ', '.join('<%s>' % x for x in recipients)
+        recipients_string = emailtunnel.abbreviate_recipient_list(recipients)
 
         if len(recipients_string) > 200:
             age = self.deliver_recipients.get(recipients_string)