SPF and DKIM are authentication protocols that are a requirement in any modern email marketing effort. The TXT records for SPF and DKIM reside in the DNS zone file for your sending domains. Without SPF and DKIM authentication, your emails might be rejected because of the lack of one or both authentication protocols.

Note: Both SPF and DKIM protocols are used for DMARC.

SPF allows the owner of a domain to specify which computers are authorized to send email that uses the "From" addresses in that domain. SPF makes use of an additional TXT entry in the existing DNS of sending domains.

What goes into a SPF record?

• Single IPs, IP ranges, or hostnames can be used. An SPF record should be as narrow as possible for greatest security so only include IPs/domains that are authorized to send emails on behalf of the sending domain.
• Email should not be sent without verified SPF authentication. There are many online tools available for this. The lack of an SPF record will hurt deliverability and will affect inbox placement.

DKIM (DomainKeys Identified Mail) allows for cryptographic signing of a portion of the email. Using DNS, the receiver can verify that the sender is allowed to send mail by using the domain that is specified in the DKIM signature and can verify that the signed portions did not change during transport.

What goes into a DKIM record?

• DKIM uses both public and private DNS keys and both keys are generated by Acoustic.
• Acoustic uses a 1024-bit encryption for its default DKIM keys.

Adding a DKIM record

Contact your Acoustic Client Success Director if you would like to have SPF and DKIM records generated for your sending domains. The Acoustic Provisioning Team will generate all necessary SPF and DKIM records that you can then provide to your IT team for implementation.

Note: Improper DNS changes that are made to other DNS records might impact website visibility or email delivery. Contact your IT department or website hosting service if you have any concerns.

More information

Several online tools are available, some of which can be found at the following websites:

• For SPF syntax help, see http://www.open-spf.org.
• For other SPF tools, see http://www.open-spf.org/Tools.
• For a DKIM verifier tool, see https://dmarcian.com/dkim-inspector/.
• For more information on DKIM, see http://dkim.org.