You've reached (someone).

Use this phrase to identify yourself on a telephone voice mail message.

When you answer the phone in person, don't use this; it's too formal. Instead, say "This is ___."

Hi Amy. This is Zack.

(someone) is not available to (do something)

When someone is "not available" to do something, it means that they can't do it; they're too busy, they have another appointment, or they're not allowed to do it.

In telephone messages, the phrase "I'm not available to take your call" just means "I can't answer the phone now."

take (a phone call)

"Taking" a telephone call means agreeing to answer it. For example, if someone calls your office, and your assistant answers, you can decide whether to "take" the call or not.

leave a message

You can "leave a message" on voice mail.

Please leave a message after the beep.

You can also leave a message with the person who answers the phone, if they're not the correct person that you want to speak to. If you call your sister's home phone, for example, and her son answers, you can "leave a message" with him. Later, he will give the message to your sister.

get back to (someone)

To "get back to" someone means to respond. You can "get back to" someone who sent you an e-mail or left a telephone message.

You can also use "get back to ___" to talk about answering someone's question later:

Please get back to me by the end of the day.