What is SPF and SenderID?

Knowledge Level:

Time: 10 minutes

Suggested Skills: Email Deliverability, Network

Objective: The easiest way to make sure your message is authenticated to improve deliverability to the inbox is to have your network administrator update your organization's SPF record. For more information on SPF and SenderID, keep reading!

References:

SPF/SenderID info:
http://www.openspf.org/

SPF/SenderID Records Lookup for a Domain:
http://www.kitterman.com/spf/validate.html

Summary:

SPF looks at the domain in the Return-Path header.

This is always @emailcampaigns.net. Looking up @emailcampaigns.net on http://www.kitterman.com/spf/validate.html gives:

v=spf1 include: emailcampaigns.net

This says all of those IP's are allowed to send for @emailcampaigns.net.  We have the records, so SPF will always pass for any email mail2 sends.

Sender-ID looks at the "Purported Responsible Address".

This boils down to the "From:" header or the "Sender:" header. mail2 does provide an option to "Authenticate This Message" which adds the "Sender:" header with a value of

"fromemail= fromdomaincom@emailcampaigns.net"

This ensures the Sender-ID checks will pass. The side effect is that it creates the "on behalf of" in some email clients.