stackshare doesn't seem to have this in the stack list yet, but in my experience Twillio is attractive. It's good for basics, their acquisition of SendGrid gives them a bit more market share.. They are stronger at marketing to those that benefit them. That said from my understanding SendGrid leases the networks, channels, and lines. While their interface is friendly, their pricing suited for lower volume, you want to look at what they are using via an API, a contract, etc. Is it a more friend UI to a combination of others. What redunancies do to they have, try their support. It's not that Twillio is bad, it's about the volume, the use case, the liabiitlies you might have to your end-users if Twillio isn't the right choice. Another option is Bandwidth. You ask for affordable, Twillio is an option, but front end costs v/s the costs of support you'll need to consider. Bandwidth has more reliability but requires more engineering and more skillset. Another option that is worth considering, not the most affordable, but https://www.zipwhip.com/ have perhaps options that might be higher and the cost is relative. Wight costs, of support costs of integration, cost of scale, costs of a volume..