Have you sent an email to the Centrum.cz (Atlas.cz, Volny.cz) address or a bank (Allianz, ČSOB, KB, Kooperativa, UniCredit, etc.) and received an error saying "Your access to this mail system has been rejected due to poor reputation of a domain used in message transfer"
The reason for this rejection is that the recipient's mail server, which uses the Cisco Talos Sender Domain Reputation (SDR)
anti-spam system, has refused the email. Your domain has not yet gained sufficient reputation (or may have a bad reputation) to be considered "trustworthy," and emails from it are not being accepted. In simpler terms, you haven't sent enough legitimate emails to recipients using this antivirus and reputation service.
Factors influencing reputation include:
- Domain age: Newly registered domains usually do not send a sufficient volume of legitimate emails to gain the required reputation at Cisco Talos.
- Sending emails from IP addresses (mail servers) that do not send spam: Our mail servers are protected against spam by the Cloudmark Security Platform (CSP) system from Cloudmark.
- The IP address from which emails are sent must have the correct reverse record - this basic requirement for a properly configured mail server is of course fulfilled on our mail servers.
How to solve the situation?
You can improve email deliverability by configuring your domain correctly:
- Set up the SPF record correctly - An SPF record including all servers used by our company for email sending is added when new hosting is setting up in case the domain also uses our DNS servers.
You can check and set up the SPF record according to the instructions in our knowledge base - Setting of SPF and DMARC records
- Sign domain emails using DKIM - DKIM signature is activated for emails sent via smtp.forpsi.com is activated when new hosting is setting up in case the domain also uses our DNS servers.
For other cases, you can use the guide provided in our knowledge base - DKIM
- Set up a DMARC record - DMARC record defines the policy for rejecting emails that do not pass SPF and DKIM checks. It will also be added when new hosting is setting up in case the domain also uses our DNS servers.
You can configure the DMARC record according to the instructions in our knowledge base - Setting of SPF and DMARC records
What if your domain and its settings are correct?
1. Delivery issues to Centrum.cz holding addresses
Centrum.cz handle the rejection of emails with a contribution in their knowledge base
. They write there, "If, even after checking the correct message settings, your emails still do not pass through our servers, contact us at the email address firstname.lastname@example.org.
Contact Centrum.cz customers support.
2. Delivery issues to other email providers
For some recipients, the chance of solution may be lower. If their support is unresponsive or doesn't solve improving of the deliverance, you can try reporting false positive reputation directly to the Sender Domain Reputation service (see below).
Report false positive reputations to Cisco Talos Sender Reputation Domain
To open a ticket, you must have Cisco account. Registration is free.
1. Account registration
- do not use characters with diacritics.
The final step is the activation of the account, which you will perform using the link delivered via email.
2. Report false positive domain
Enter your domain(s) in the form
Click on the button Add Entries to Ticket.
Ensure you have selected NOT MALICIOUS reputation.
If you have the rejected email, attach it to the ticket using the ATTACH FILE button.
All tickets are available upon logging into the account. Information about the change in ticket status (resolution) is delivered to the email address provided during registration.