I cant fax
Take your cell-phone, and dial the same number, to see if you get the same "busy" signal.
If the telephones in your business require you to "dial-9" to get an "outside" line, be sure that your FAX is also following that "dial-9" protocol, and also waiting 1 or 2 seconds after the "dial-9", in order to get the dial-tone from the "outside" line.
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