Why did an invoice was undelivered to an address that had been used before?

[JMF21]

does anyone know what to do when it saying undelivered for an invoice , due to the email address? im confused bc this customer has paid me before and i sent invoice to the same email

The title of this post has been edited from the original: "undelivered for an email address but this customer has paid before with the same email"

[TheRealChipA]

Hi @JMF21.  There are lots of reasons for this.  The customer could have changed their email address and deleted the one you have on file.  Their email box could be full.  Their email service could be suspended for some reason.  Their email service could be having technical issues.  And the list goes one.

My recommendation would be to look at their customer record and see if you have a phone number on file you can use to contact them. 

Good luck.