Fortimail VM01 DNS UDP Errors

Hey Folks

I have recently seen the following system events in two of our Fortimail VMs.

 

dns DNS: No UDP response from server ********* (warning->alert). alert   dns DNS: Server ******** is not reachable or is responding slowly via UDP (alert->warning). warning   I have tested our DNS Servers and they ar working like they should. No other problems at all. Even opened a Ticket at Fortinet, but the engineer didn't find out yet what the problem is.   I actually don't even know if this really is a problem. I came across the errors while analyzing a problem with sending a mail to an external receipient.   Thanks in advance for any tipps.