I have an update.
I had some issues in tuning the storage that showed latency peaks over 200 ms.
Now i made some changes and the latency is under 10ms but the job still crash (even if it last for more minutes than before, ).
I'm wondering where can it be the bottleneck:
Mailserver0:
CPU OK (8 core assigned, always <70% )
RAM OK (8 GB, always <5GB allocated )
Net OK (10Gbit/sec)
Storage OK ( latency <10ms )
in attachment the last job failed.
Regards.