stop MAIL UNDELIVERED warning coming through for days

[unwashed potato!]

if someone puts an incorrect email in the quote form, we will sometimes get an auto reply like the below:

This message was created automatically by mail delivery software.
A message that you sent has not yet been delivered to one or more of its
recipients after more than 48 hours on the queue on raven.footholds.net.

The message identifier is: 1hpb2y-008t2q-DL
The subject of the message is: Re: Quote Ref 072213_2671
The date of the message is: Mon, 22 Jul 2019 17:20:20 +0100

The address to which the message has not yet been delivered is:

[email protected]
host livr.com [35.186.238.101]

No action is required on your part. Delivery attempts will continue for
some time, and this warning may be repeated at intervals if the message
remains undelivered. Eventually the mail delivery software will give up,
and when that happens, the message will be returned to you.

this doesn't happen all the time, but just some random emails it'll come back like this, and what's more annoying, we will get this email every day for the next week or so.

anyone know how we can stop this and why it happens only to some incorrect email addresses?

i'm with tsohost, and they said nothing can be done. seems like bs to me

 

[unwashed potato!]

set up and email rule and send them to the deleted/spam folder?

From the server end or my email client?