Users often don’t invest enough time into their messages, resulting in incomplete, unprofessional, or otherwise under-whelming greetings. Sure, crafting a greeting doesn’t sound all that complicated; however, there are a number of pitfalls users can fall into—i.e. informality, terseness, sincerity, lack of direction, and more. While none of these sound too catastrophic, they are often interrelated. As such, they tend to worsen any problem. For example, humor can cause informality, worsen ambiguity, and weaken sincerity. That being said, users should strive to avoid ALL these pitfalls.
The insurance agent is quite polite in his approach towards his clients. He is also eager in extending his help to the client.

When calling any business number, you are often greeted with an automated voicemail greeting that helps guide you through the company directory, hours of operation, contact information and alternative steps for the call, such as leaving a message.
Expand your message with 'We're sorry we couldn't take your call this time.' The inclusion of 'this time' or 'on this occasion' suggests that the voicemail is the exception rather than the rule.