Voicemail functionality was initially implemented for Twilio as a quick fix after realizing the company had not wired its 877-8-TWILIO phone number to anything before launch, with the solution being a simple voicemail application that records messages and emails them to the team. However, this simple solution quickly became problematic due to poor management of incoming messages, prompting Twilio to develop a better solution to manage volume, answer calls personally, and ensure timely response to voicemails.