This may be because DMARC, DKIM, and SPF need to be set up on your DNS.
(usually WebCentral/GoDaddy or similar)

What are DMARC, DKIM, and SPF?

DMARC, DKIM, and SPF are three email authentication methods. Together, they help prevent spammers, phishers, and other unauthorized parties from sending emails on behalf of a domain* they do not own.

DKIM and SPF can be compared to a business license or a doctor’s medical degree displayed on the wall of an office — they help demonstrate legitimacy.

Meanwhile, DMARC tells mail servers what to do when DKIM or SPF fail, whether that is marking the failing emails as “spam,” delivering the emails anyway, or dropping the emails altogether.

Domains that have not set up SPF, DKIM, and DMARC correctly may find that their emails get quarantined as spam, or are not delivered to their recipients. They are also in danger of having spammers impersonate them.

If you require assistance with the below, please advise your SMTP2GO.com login & password as well as your login & password for your Domain Name Registrar (usually WebCentral/GoDaddy or similar)

To use SMTP2GO for authenticated email delivery, follow these required steps:

  1. Sign up and log in to your SMTP2GO account.

  2. Add your sender domain:

    • In the dashboard, go to Sending > Verified Senders > Sender domains.

    • Click “Add sender domain,” enter your domain (e.g., example.com), and continue.

  3. Collect your DNS records:

    • SMTP2GO will display three CNAME records for your domain:

      • SPF CNAME for return-path alignment and SPF authentication.

      • DKIM CNAME for cryptographic email signing.

      • Tracking CNAME for open/click tracking and bounce handling (optional but recommended).

  4. Add the provided CNAME records to your domain’s DNS at your DNS host/provider:

    • You do not need to manually add or modify SPF or DKIM TXT records—just the provided CNAMEs.

    • Wait for DNS propagation, which may take up to 24 hours.

  5. Validate domain in the SMTP2GO dashboard:

    • Return to the “Verified Senders” section.

    • Click “Validate” after DNS changes.

    • The status should change to “Verified”—you can now send from any address at that domain.

  6. (Recommended/Required for bulk senders) Add a DMARC TXT record:

    • Separately in your DNS, add your preferred DMARC policy (e.g., v=DMARC1; p=none; rua=mailto:[email protected]) to protect your domain and comply with bulk sender requirements (mandatory for Gmail/Yahoo senders over 5,000/day).

Key notes:

  • Do not manually update your primary SPF or DKIM TXT records for SMTP2GO—use only the CNAMEs provided.

  • If you can’t add DNS records, you may instead verify a single sender email address, but this is not recommended due to loss of SPF/DKIM alignment and lower deliverability.

  • Once verified, you can start sending authenticated and aligned email through SMTP2GO.

These steps ensure your email passes all deliverability, security, and compliance checks.