Some people choose to use Smartbnb to handle messaging. Smartbnb can be used in conjunction with OwnerRez, if you set it up correctly.
The only adjustment you'll need to make is with your automated messages. If you choose the "Jumpstart" onboarding option during your Smartbnb account setup, automated messages are enabled. This could cause a duplicate new reservation message if you already have that message configured inside OwnerRez.
Since automated messaging is the main reason someone would use Smartbnb, we suggest configuring your Smartbnb messaging and then disabling your automated messages inside OwnerRez. This way you will not be sending out duplicate messages.
Here is the document Smartbnb provides: https://help.smartbnb.io/en/articles/5268781-i-m-already-using-software-can-i-still-connect-to-smartbnb