diff --git a/roles/mailman/templates/mm_cfg.py.j2 b/roles/mailman/templates/mm_cfg.py.j2
index b0cd8f899fbdccd3fc0cde126210d0fedee3e701..48b48fb8b35b685331d4389c2dcc239773f48699 100644
--- a/roles/mailman/templates/mm_cfg.py.j2
+++ b/roles/mailman/templates/mm_cfg.py.j2
@@ -127,6 +127,10 @@ SMTPHOST = 'mail-frontend.{{ domain }}'
 SMTPPORT = 10025
 SMTP_HELO_HOST = '{{ shard_id }}.mailman.{{ domain }}'
 
+# Establish a new SMTP connection for every session, to effectively 
+# load-balance outbound email among available mail-frontend servers.
+SMTP_MAX_SESSIONS_PER_CONNECTION = 1
+
 DEFAULT_ARCHIVE = Off
 DEFAULT_ARCHIVE_PRIVATE = 1
 ARCHIVE_TO_MBOX = 2