SMS Gateway for Marketing Campaigns

I am looking for a proficient SMS sender gateway for my marketing campaigns. The system should cater to the following needs:

- Bulk Sending: The ability to send messages to a large audience simultaneously is crucial.
- Personalized Messages: I want to connect with my customers on a personal level, hence, the need for sending customized messages.
- Scheduling Messages: I need the flexibility to plan and schedule my messages ahead of time.

Please note, I do not currently require integration with any specific marketing platforms. However, the ideal candidate should have prior experience in developing or working with SMS gateways and should be able to demonstrate the capability to handle these tasks efficiently.

I Need to have my own routes.