diff --git a/modoboa/core/models.py b/modoboa/core/models.py
index c6f89ae19..fed83e3f7 100644
--- a/modoboa/core/models.py
+++ b/modoboa/core/models.py
@@ -1,5 +1,6 @@
 """Core models."""
 
+from email.header import Header
 import re
 
 from django.core.urlresolvers import reverse
@@ -223,10 +224,9 @@ class User(PermissionsMixin):
 
     @property
     def encoded_address(self):
-        from email.header import Header
         if self.first_name != "" or self.last_name != "":
-            return "%s <%s>" % \
-                (Header(self.fullname, "utf8").encode(), self.email)
+            return '"{}" <{}>'.format(
+                Header(self.fullname, "utf8").encode(), self.email)
         return self.email
 
     def is_owner(self, obj):
diff --git a/modoboa/lib/email_utils.py b/modoboa/lib/email_utils.py
index 4f9a19c39..be8a6a411 100644
--- a/modoboa/lib/email_utils.py
+++ b/modoboa/lib/email_utils.py
@@ -276,6 +276,8 @@ def prepare_addresses(addresses, usage="header"):
     """
     result = []
     for address in re.split('[,;]', addresses):
+        if not address:
+            continue
         name, addr = parseaddr(address)
         if name and usage == "header":
             result.append("%s <%s>" % (Header(name, 'utf8').encode(), addr))