I am having the same issues invoices I have sent to customers for years now bouncing, getting really pissed of as a one man band I don't have time to chase everything up I have resorted to sending nvoice to me me then saying as a PDF  then forwarding to the customer not exactly user friendly, another thing that pees me of if I have a Mrs Smith at one address and another Mrs Smith and another address, you have to modify the name to add it to the system as Smith is already on the data base I'm thinking of going back to easy invoicing I used for years always got through no conflict with customers names  only no bank reconciliation but maybe a price worth paying also one payment , a lot less than paying for something that doesn't work for me.