Hi [first-name],
I just left you a voicemail a few minutes ago, and I figured I would follow up with an e-mail so you have my contact information. Feel free to reach out to me when it is convenient for you, or let me know a good time to reach out to you if you have a busy day.
Thank you!
[your-business-name]
Austin Daniel
Sales Development Representative
P: [your-phone-number]
[your-email]