iDRAC 9- configure DNS for enable email Alerts. risk???

Hi

I am tryng to enable e-mail alerts on iDRAC 9 enterprise, but I saw that i need to enable DNS on my iDRAC, 

my doubt if 

• are there any risk that I have to know before enable it? 

Actually my company have more than 1 DNS, wich should I have to enable on my iDRAC to enable de e-mail alerts?

• What happend if I set the wrong DNS? is there any risk whith that?

thanks.