Even with Gmail you are going to run into deliverability issues, which in any line of business, is not something that can be afforded when it can be avoided for a small fee.
It's going to cost you a little money (maybe take it out of your workers commissions) but it's a much better solution and your deliverability rate will increase. Try an MS Exchange box:
https://products.office.com/en-us/ex...xchange-online
There are many different providers so feel free to shop around until you find somebody that you like. Give it a whirl. Thank me later.
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