1 files changed, 10 insertions, 0 deletions

diff --git a/src/mailman/interfaces/mailinglist.py b/src/mailman/interfaces/mailinglist.py
index ddc5a13b6..f066ba3c8 100644
--- a/src/mailman/interfaces/mailinglist.py
+++ b/src/mailman/interfaces/mailinglist.py
@@ -18,12 +18,22 @@
 """Interface for a mailing list."""
 
 from enum import Enum
+from mailman.interfaces.address import InvalidEmailAddressError
 from mailman.interfaces.member import MemberRole
 from public import public
 from zope.interface import Attribute, Interface
 
 
 @public
+class InvalidListNameError(InvalidEmailAddressError):
+    """List name is invalid."""
+
+    def __init__(self, listname):
+        super().__init__('{}@'.format(listname))
+        self.listname = listname
+
+
+@public
 class DMARCMitigateAction(Enum):
     # Mitigations to apply to messages From: domains publishing an applicable
     # DMARC policy, or unconditionally depending on settings.