when OTRS reopens consistently the tickets you have several options to resolve an issue
1. Disable state change with following options
PostMasterFollowUpState='open' # to keep ticket open
PostMasterFollowUpStateClosed='closed' # to keep ticket as closed if it was already closed
2. Disable followup mails individual per queue in Queue-Admin management using FollowUp combo box.
It exists also undocumented feature you can set default value for combo in Config.pm file
# 1-possible, 2-reject, 3-create new ticket
$Self->{'AdminDefaultFollowUpID'} = "3";
Enjoy!
