Welcome to SPF records scanner

SPF record scanner is a project of Virginia Tech. We send “one” single email to a MX server to let it look up our SPF records (please note that we do NOT scan your SPF records). The purpose of this measurement is to better understand how recipient SMTP servers correctly verify our SPF records.

What can mail server operators expect?

Mail Servers

You can expect that you will receive a single email from our server. We do NOT send multiple emails from our measurement node. If you have received multiple emails from our measurement node, this should be corrected from our end. We do aplogize in advance and please contact us (with the below format)

DNS Resolvers

You can expect that the DNS resolvers that your SMTP server use send DNS queries such as NS, A, MX, SPF records. Please note that your SMTP server will just send one DNS query to the DNS resolver, which looks up the name on behalf of you.

What should I do if the measurement impacts on my infrastructure?

As our measurement only sends “one single” email to a recipient SMTP server, but if you notice that your email servers keep receiving emails from our end, impacting your infrastructure adversely, please contact us so we can try to resolve the problem. We would be highly appreciated if you could send us the following information:

• The name of your organization and an email address,
• The DNS hostname(s) of the affected name server(s),
• The MX record(s) of the affected mail server(s),
• A brief description of the impact,
• A date and time on which you (first) experienced problems you think may be caused by our measurement,
• The IP address(es) or block from which you are receiving problematic traffic.

Upon receiving the information above, we will stop sending any queries and fetching certificates from the DNS servers and mail servers.

Response Time

We are in the EDT (Eastern Time, UTC-4). We try to answer any request concerning problems within one business day. If you need our urgent attention, please include “[URGENT]” in the subject line of any e-mail you send us.