Invoice pdfs not received by email recipient.

Sally Telfer_8103851
Sally Telfer_8103851 Member Posts: 4
edited February 2020 in Accounts Hosted
I am having complaints from my clients over the last two months that they are not receiving the pdf attachments of invoices witht he emails. I have not upgraded windows or made any other change. Is this my system or theirs? any ideas on how to correct this?