The difference is subtle and primarily reflected in how we choose to deliver pre recorded phone calls to our customer's contacts. When you think about phone dialers, you’re talking about a service that makes phone calls to connect someone to a live person - typically for the purpose of selling or qualifying a lead.
In Australian English it’s pronounced with the vowel /a:/ like in ‘part’. Problems arise when people use the /ʌ/ vowel (like in ‘up’) instead of /æ/ or /a:/. If you do this is will sound like the worst swear word in English. Many non-native speakers often pronounce the vowel /æ/ more like /ʌ/ because they don’t have a vowel like /æ/ in their first language. Many speakers of European languages will do this (Spanish speakers and Italian speakers) and also speakers of Japanese and Korean. This problem with /æ/ also means that if you say the word ‘back’ in your voicemail greeting sample, you are likely to pronounce it more like ‘buck’. remember to pronounce word endings in English. Check you aren’t dropping any endings off or mispronouncing them.

Hello, you have reached the food delivery services of X. I am currently speaking to a customer and will not be able to take your call now. If you want some urgent delivery of food items, you can call our other number Y and place your order. Otherwise, kindly leave your details like your name, contact number and your order details so that I can get back to you for confirmation. Thanks for your cooperation.
You could add the words "After-Hours Service" or "After-Hours Line" after the company's name. That way there's no concern over whether it is indeed a number that reaches a real person who will return their call during non-business hours. It's a way to let them know they're on the right track. If that makes sense. :)