Phone number masking by Twilio

We need client masking . 2 ways to connect 1. Is with call and sms from and to client 2. Is email from and to the client. We need masking for both. For first it can be done with twilio. Second we have been suggested that it can be done with SendGrid. We are not sure about the same. You have to check and implement if that is possible. You can suggest how we can do and what is the best and secure way to implement it on web or mobile. Our preference is web-based. So that they can do all from one laptop only. Call, sms and e-mail. We are currently using ring central and we have 4 numbers. Uk, Canada, AUS, Nz. We are looking for an Indian number to be connects as well. We'll be uploading leads/contacts in the database for which our agents can search and message/call/email. For future we are looking to integrate these 2 things with Zoho as well.