Melissa UK Team | United Kingdom

Some mail providers have additional authentication systems in place such as SPF, DKIM, and DMARC which may prevent your email from making its way into your recipient’s inbox. These authentication protocols are designed as a response to increased spam and fraud within the email industry. The more authentications that are in place by the receiving mail server, the more secure the email process is. However, this means that there is a higher chance of undeliverable emails because of a misconfiguration on the sender’s side of things. We expect the email industry to move towards widespread adoption of these authentication protocols in the near future.

Global Email can identify which authentication systems are in place for the MX server of the email during validation, so you can make changes to your MX server settings and improve deliverability prior to actually sending out the email.

SPF – Sender Policy Framework – This is an authentication protocol from the sender that lists out IP addresses in a DNS TXT record that are authorised to send emails on behalf of the sender’s domain. The receiving system will get a status on whether or not an SPF record was received.

If the receiving mail server requires SPF:

• If the sender’s SPF record is valid and your IP is on the list, your email will make its way into their mailbox.
• If the sender’s SPF record is non-existent, there are no checks and your email will make its way into their mailbox.
• If the sender’s IP is not on the sender’s record, the sender will fail the SPF check when the SPF record is sent to the recipient’s mail server. Your email will be rejected or go into the spam folder.

If the receiving mail server does not require SPF:

• Your email will make its way into their mailbox.

Best Practices for SPF:

Always make sure that the server responsible for sending emails out has a valid SPF record with that server’s IP address whitelisted.

DKIM – Domain Key Identified Mail – This is an authentication that provides a way to validate a domain’s identity with cryptographic authentication. This signature verifies that the message is authentic and that the original message is not modified. Outbound email servers with DKIM setup will attach a DKIM so that the receiving server can verify it.

If DKIM is optional or not required at the receiving mail server:

• Your email will make its way into their mailbox.

If DKIM is required at the receiving mail server:

• Valid DKIM means your email will be accepted.
• Depending on the policy set, No DKIM means accepted, rejected or will go into the spam folder.
• Depending on the policy set, Invalid DKIM means rejected or will go into the spam folder.

Best Practices for DKIM:

Always make sure that the server uses DKIM authentication for outbound emails.

DMARC – Domain-based Message Authentication, Reporting & Conformance – This authentication prevents unauthorised use of a domain in a domain spoof or phishing by evaluating the “from” portion of the email. The protocol allows the receiving mail server to see the origin domain from which the “from” address is being sent. Mail servers can then set a policy at the DMARC DNS record to determine the fate of unauthorised emails.

If DMARC is ignored at the receiving mail server:

• Your email will make its way into their mailbox.

If DMARC is checked at the receiving mail server:

• If the email is authenticated, your email will be delivered.
• If the email is not authenticated, your email will be delivered, sent to spam or rejected based on the policy set (none, quarantine, reject).

Best Practices for DMARC:

Always make sure that the domain the server uses to actually send out the email matches the domain of the “from” email.

Conclusion

Following best practices for DMARC, DKIM, and SPF + utilising email validation will result in:

• Maximising your email deliverability and improving ROI on leads      
• Reducing bouncebacks and timely/costly IP reputation damage      
• Reducing spammer designations
• Increasing email security and adherence to industry-standard protocols

Melissa’s Global Email Verification Service can remove up to 95% of bad email addresses – helping you increase deliverability, avoid high bounce rates and blacklisting, protect your valuable sender reputation and improve your data quality. Our solution verifies emails in real-time, pinging each email to ensure it is active and able to receive mail, corrects typos and illegal characters, and detects mobile email addresses that shouldn’t receive commercial email messages. Check out our recent blog post on Global Email V4 to learn about new release improvements and features, or take a look at the Quick Start Guide.