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.
Though it may seem weird and nonsensical to you, it really works. When you smile as you speak, you are able to sound happy, cheerful, and upbeat. Don’t knock it ‘til you try it.

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.
The above eight rules of engagement for voicemail greetings may sound easy enough, but they’ll require some practice to get just right. Let’s look at some examples to provide some context in how to apply the rules to various types of greetings and situations.