Hey - We're currently sending monthly statements to our customers in PDF using Optio. Is there a reporting function or a way to designate a general box to receive input for undelivered messages when the email address is invalid?
Not automatically. Your Optio statements are going out through a SMTP gateway on your mail server, right?
Handling rejected /returned email is a function of your mail server which you may be able to script to find the reject mails you care about.