I have a department that uses a cloud base software and they claim that their auto generated emails are being delayed.

Because of delayed emails the vendor has requested that we add them as a "trusted domain" so their emails will come quickly without delays.

Is this a good idea?  If so, how do I do this?

Ex2013/Win2012

Hi,

You can try to use the below command to add domain A as a safe senders :

Set-MailboxJunkEmailConfiguration -TrustedSendersAndDomains "<domainA>.com"

More detailed information, please refer to the below link:

https://support.microsoft.com/en-us/kb/2545137

Regards ,

David