- Select Mail Flow > Send Connectors 
- Click + to add a new send connector 
- Enter Vaultastic in the Name field. 
- Select Custom as the Type option 
- Click Next 
- Under the Network settings, select Route mail to smart host 
- Click + to add a new smart host 
- Enter the FQDN (fully qualified domain name) of the Vaultastic server in the format o365-v4.vaultastic.com . Click Save 
- The new host will be listed under Smart Host in the New Send Connector Window. Click Next 
- For the Smart host authentication, select None option. Click Next. 
- Click + to add a new address space. Enter the FQDN as {domainprefix}.vaultastic.com server. Click Next. 
- Click + to select. In the pop-up dialog, select the source Exchange server, then click Add. Click OK. 
- Click Finish. 
