Invoice sent but not received /resent via Gmail - with wrong account
We sent 11 invoices to a Travel Agency that we have been working with regularly. As all invoices were overdue, we phoned and asked them what the problem was. They replied that they had not received any of the 11 invoices, all sent via Wave with copy to me. Copy to my own inbox arrived immediately (and in previous months also arrived @ accounts department of the TA) They checked Spam folder without finding any of the invoices. Any ideas of what the problem could be? Other invoices sent to other TAs were received as usual.
Follow up question:
I then resent the invoices via Gmail. Is there any way to choose which Gmail account is used? In Wave, the primary email listed is the business account, used to send the invoices and which I thought would be used. But the mails all were sent via my private account which is not even listed in my WAVE profile. This is troublesome as any replies will now come into another account that is not at all related to the business.
Does anybody have any thoughts or solutions to these problems? Thanks