How to send group messages to mobile phones by computer?

Actually, it's really simple. The computer sends it to the mobile phone in two steps:

Collect everyone's cell phone numbers. Completed in excel spreadsheet. This is relatively simple, that is, counting mobile phone numbers.

After the content of the short message is agreed, write it in the above soft interface, then import all the numbers and copy them, and then there is a button to delete the wrong number, which will arrive in 3 seconds.