American Express unable to email Virgin Media customers - IP Address Blacklisted

I reported this issue about 5 weeks ago and have not received any updates from Virgin Media. Ticket number: P012878341. It’s been ongoing since at least October 2024. American Express are unable to send emails to Virgin Media customers with @virginmedia.com or @ntlworld.com email addresses. Virgin’s email servers are blocking American Express’ email servers and as such emails are not being delivered.

I am unable to receive critical and important emails from American Express (@aexp.com) email addresses because Virgin Media SMTP servers are blocking email from American Express sending servers. Specifically the following AMEX servers are blocked:

139.71.95.77
139.71.95.78
139.71.1.77

When American Express attempts to send emails to myself and other Virgin Media customer’s email addresses, the Virgin Media servers reject the emails with the error:

550 Reverse DNS for your IP is blacklisted here

Example sending email address: UKBereavementSupport@aexp.com.

Please can somebody help to escalate this issue.