Afilnet is one of the best SMS provider in the market, we have been working with this company for the last 10 years, and we're really happy with the service and support given.
Pony Express HQ - Pony Express HQ is an SMS text message marketing for small businesses, real estates, clubs, communities, dispensaries or non-profits. Send and receive text messages and images online with the large group of customers. Group texting app no reply all.
Addressify - Addressify is an API that allows developers to implement address verification, validation and autocomplete for Australia in their apps.
Releans - Communication platform for Messaging and Chatbots
Smarty - Smarty provides address validation, autocomplete, geocoding and reverse geocoding services covering addresses in over 240+ countries.
Twilio - Brings voice and messaging to your web and mobile applications.
Experian Address Verification API - Experian provides Address Verification API for accurate, complete USPS addresses with minimal data entry.