Would this affect emails getting through to Virgin Media accounts (including blueyonder and ntlworld)? I work for a large retailer and have noticed a significant increase in the number of blocked emails since around 21st May. The error message we are seeing is "452 4.1.1 <email@example.com> requested action aborted: try again later;" Any insight into what is causing this would be appreciated, as it is causing great inconvenience to our customers as they are not receiving important service emails regarding their order.
Thanks for your post and welcome to the Community Forums, This POP3 authentications issue should not be generating that delivery error. Have you checked to see if your domain is listed among any of the mail deliver services for delivery issues?
As a rule I'd always recommend checking the IP address of your outbound mail server rather than the domain. Bear in mind also that while Spamhaus is one of the most well known of the Blacklist providers, they're not the only provider there is.