diff --git a/smeserver-dovecot.spec b/smeserver-dovecot.spec
index 32547a3..26d19cf 100644
--- a/smeserver-dovecot.spec
+++ b/smeserver-dovecot.spec
@@ -1,5 +1,5 @@
 %define version 11.0.0
-%define release 11
+%define release 12
 %define name smeserver-dovecot
 
 
@@ -41,6 +41,9 @@ Configure the dovecot IMAP server with sieve scripts support,
 quota, ACL, extended logging, master user
 
 %changelog
+* Wed Sep 25 2024 Jean-Philippe Pialasse <jpp@koozali.org> 11.0.0-12.sme
+- fix missing sharedmailbox group [SME: 12735]
+
 * Tue Sep 24 2024 Jean-Philippe Pialasse <jpp@koozali.org> 11.0.0-11.sme
 - add missing /home/e-smith/files/public/ folder [SME: 12735]
 
@@ -271,6 +274,9 @@ if [ $1 -gt 1 ] ; then
   fi
 
 fi
+
+/usr/sbin/groupadd -g 439 sharedmailbox 2> /dev/null || :
+
 %post
 
 %preun