Talking only for email. 

Zoho Mail is free unless you need it for a large team. The basic version will serve you very well.

Namecheap offers paid options. But as a company, we use Zoho for its better user interface and features. 
 

Thanks ​@Mahmodul !

P.S. Hospitable is currently working on a feature that will allow sending emails from custom domains using Mailgun⁠. This is still in progress, but once launched, it will be possible to use branded email communication for Direct, Manual, and Agoda listings.