833-877-7249

left voice message when I called back from post office doesnt looks like legit post office number.

Your details are vague and contradictory.  If you called & spoke to someone at your local post office, why would you need to call the number left in a voicemail?   Here's a quote directly from USPS:
"Why would USPS be calling me?
The caller will explain that there is a package waiting to be delivered, but only after personal information is verified. Don't take the bait. The U.S. Postal Service® does not call customers about package deliveries and they will never request personally identifiable information for delivery verification purposes."

Web search on this number shows that it associated with robo calls. Severity of the calls indicated as 'Severe'. Another Red Flag was that 833 number. In most cases, Big government outfits will have 800 numbers.
The post you replied to was a shill (or someone VERY confused) and was reported for removal.

To Future Readers and Posters: This number is NOT safe. It is used by scammers in a US Post Office scam. Do not call this number back, you will be talking to crooks.

said they were calling from USPS and got my information (including my address they read back to me) from my local post office as someone who could use additional services.  Asked what I am shipping and I was vague and just said ebay.  I reverse searched while on the phone and saw it was a scam number.  I hung up and called my local post office.  My post master did not give my information out.  they tried calling back while I was on the phone with my post office.  They sound convincing SO BEWARE!

Transcript from voicemail: Good morning. My name is Joseph sandozi bugs. I'm with the United States Postal Service. I'm reaching out to provide information regarding our newest commercial Solutions. If you're interested in learning how I can assist you in your business. Please give me a call back at 833 8777249. Again, that number is 833 877 7249. Have a blessed day. I look forward to hearing from you.

Rec’d call from this number. I do have a small online business and I shipped  a lot of things packages via USPS. They left following VM-
“Hello my name is Tonya Keel with United States Postal Service I'm reaching out to provide information on our newest commercial solution if you're interested in learning how we can assist you in your business please give us a call at 833-877-7249 again that number is 833-877-7249 we look forward to speaking with you soon thank you…”

Not from what a simple web search shows. BTW, do you always lookup and post about numbers that you know are "legit"? Seems like something a shill would do.

To Future Readers and Posters: This number is NOT safe. It is used by scammers in a US Post Office scam. Do not call this number back, you will be talking to crooks.