Overview

Sender authentication is a critical technology that will help solve several of acute problems with email today, including fraud, spam and false positives.

Port25 has taken a leadership role in helping make sender authentication a reality by actively participating in the standards development efforts and by being first with product offerings that help make it easy for legitimate senders to adopt email authentication.

If you have questions or need additional support regarding Sender Authentication, please submit a request using the form below.

Port25 Resources

Features in PowerMTA that help you adopt email authentication including support for Yahoo's DomainKeys and Microsoft's Sender ID.

PowerPoint presentation given on November 18th, 2004 at the Inbox Event in Atlanta: "Sender's Guide to Sender ID".

To use our automated testing tool, send a sample of a marketing email or newsletter to get the summary results. Senders can choose where the results should be sent:

• If you wish to receive the results at the address in the "mail_from," the sample message should be sent to check-auth@verifier.port25.com.
  
  
• If you wish to receive the results at the address in the "from" header, the sample message should be sent to check-auth2@verifier.port25.com.
  
  
• If you wish to receive the results at a different address from one of the addresses above, the address need to be added to the check-auth address. For example, to send the results to:
  jsmith@yourdomain.com
  the sample message should be sent to
  check-auth-jsmith=yourdomain.com@verifier.port25.com.

A reply email will be sent back to you with an analysis of the message's authentication status. The report will perform the following checks: SPF, SenderID, DomainKeys, DKIM and SpamAssassin.

Timeline

Here is timeline of key events in email authentication for Port25:

May 24, 2004: Port25 first to announce support for Yahoo's DomainKeys

August 31, 2004: Port25 first to announce support for Microsoft's SenderID

September 20, 2004: Port25 Releases PowerMTA 3.0, includes features to help senders adopt email authentication

November 9, 2004: Port25 Presents on the State of Email Authentication at FTC Summit in Washington, DC

November 17, 2004: Port25 Adds Native Support for Habeas Sender Warranted E-mail

November 18, 2004:Port25 Presents "Sender's Guide for Sender ID" at Inbox Event in Atlanta, GA

May 11, 2005: Port25 Joins Industry Coalition to Drive Adoption of Email Authentication.

May 24, 2005: Port25 Solutions Participates in CAN-SPAM Panel at Inbox West 2005

August 23, 2006: Port25 Solutions Announces Support for Goodmail CertifiedEmail on Windows; Additional Scalability on 64-Bit Linux Systems; first MTA solution certified and approved by Goodmail Systems

 

Other Resources

General Information
www.microsoft.com/senderid
spf.pobox.com/
antispam.yahoo.com/domainkeys

Whitepapers
spf.pobox.com/whitepaper.pdf
www.sendmail.net/

Testing Tools
www.port25.com/auth
spf.pobox.com/why.html
senderid.espcoalition.org/

Wizards
www.anti-spamtools.org/
spf.pobox.com/

Discussion Groups
spf.pobox.com/mailinglist.html

RFC's
http://www.ietf.org/rfc/rfc4406.txt
http://www.ietf.org/html.charters/dkim-charter.html

Benchmarks
www.sendmail.net/dk-milter/benchmark/

Consulting Services and Support
spf.pobox.com/services.html