Customers still have this kind of issues. Below is one example of emails from customer about it.
"Unfortunately I'm still not getting order confirmations. So I'm now missing a further two invoices - for Dec 5 (02745) and Jan 14 (02876).
Please can you send me these invoices? I need the Dec one ASAP as my accountants will be submitting my latest VAT return next week.
Please can you look into, and come back to me on, what's going wrong in the system? I used to get the order confirmations and haven't changed anything at my end, so not sure why this started happening in Nov.
Cheers
Tash"