It's possible to create an email which can be stuck while being processed by PostMaster filters causing DoS. This issue affects: OTRS AG ((OTRS)) Community Edition 6.0.x version 6.0.1 and later versions. OTRS AG OTRS 7.0.x version 7.0.28 and prior versions; 8.0.x version 8.0.15 and prior versions.