Unexplained blocked email address

Question

Unexplained blocked email address

Russell Shaw 5

Hello. I am trying to work out why emails from a senders address keep failing to be delivered. I have purchased rail seat reservations from Rail Europe, and upon completion of the purchases they have made multiple attempts to email me the confirmation document, with PDF reservations attached, but these emails never reach my account, in either the inbox or the junk mail folder. I have made enquiries with their help desk who are able to send me email replies from their email address that do get delivered.

The help desk emails are from: ******@raileurope.com

The emails that are not getting delivered are from: ******@raileurope.com

I have both of these addresses in my contacts and safe senders lists, so I can only assume that the emails are being blocked before they even reach my account. Can you please help?

Regards. Russell Shaw

DiamondD 5 Reputation points

2026-02-25T19:35:31.6066667+00:00

Outlook servers at least in the US are absolutely blocking mails from the @raileurope.com server. No rules present, emails never arrive. Emails are received within 5s to @gmail.com accounts or at least intermittently letting them through.
Russell Shaw 5 Reputation points

2026-02-26T06:49:03.06+00:00

Cheers DiamondD. So it's not just my account then. Starting to sound like I need a different email provider :(

1 answer

Your answer

DiamondD 5 Reputation points

2026-02-25T19:35:31.6066667+00:00

Outlook servers at least in the US are absolutely blocking mails from the @raileurope.com server. No rules present, emails never arrive. Emails are received within 5s to @gmail.com accounts or at least intermittently letting them through.
Russell Shaw 5 Reputation points

2026-02-26T06:49:03.06+00:00

Cheers DiamondD. So it's not just my account then. Starting to sound like I need a different email provider :(

Answer 1

It sounds like the emails from Rail Europe are being blocked before they reach your account, which can happen for various reasons. Here are a few steps you can take to troubleshoot the issue:

Check Blocked Senders List: Ensure that the sender's email address is not on your blocked senders list. Sometimes, addresses can inadvertently be added.
Review Non-Delivery Reports (NDRs): If you have access to any non-delivery reports (NDRs) related to these emails, they can provide insight into why the emails are not being delivered. Look for error codes such as 5.7.511 (banned sender) or 5.7.513 (client host blocked).
Contact Rail Europe: Since their help desk can send you emails successfully, ask them to verify if their sending IP address is on any blacklists or if there are any issues with their email configuration.
Use the Delist Portal: If you suspect that the sending IP may be blocked, you can advise Rail Europe to use the Office 365 Anti-Spam IP Delist Portal to request removal from the blocked senders list.
Check Email Authentication: Ensure that Rail Europe is following best practices for email authentication (like SPF, DKIM, and DMARC) to improve their email deliverability.

If the issue persists, you may want to reach out to your email provider for further assistance, as they can provide more specific insights into the email filtering that may be occurring.

References: