aql API

From their site: aql.com is the award winning SMS solutions portal (formerly known as sms2email). We are dedicated to getting your SMS marketing campaign or interactive service working with us. Our services include bulk messaging through a number of routes offering high reliability along with different pricing options. Every aql account includes the free textback service, an easy way to enable your target audience to reply to you. The service is available globally with pricing for global use and for use within the uk.