DKIM record for SMTP2GO

The DNS records

SMTP2GO generates the host names for each domain; the targets are fixed. The DKIM host below is a placeholder.

DKIM

Type: CNAME · Host: <selector shown in SMTP2GO>._domainkey Copy

dkim.smtp2go.net

Return path (SPF)

Type: CNAME · Host: em12345 Copy

return.smtp2go.net

em12345 is SMTP2GO's example. Point it at return-alt.smtp2go.net instead if you need an SPF hard fail (-all).

Link tracking

Type: CNAME · Host: link Copy

track.smtp2go.net

Not part of authentication: once verified, SMTP2GO requests a certificate so tracked links use https.

Set it up and turn on signing

1. In the SMTP2GO dashboard, open Sending > Verified Senders > Sender domains, click Add sender domain and enter the domain (for hello@exampledomain.com, enter exampledomain.com).
2. Pick manual or automatic setup. The automatic option logs in to your DNS host through Entri; SMTP2GO says it doesn't store those login details.
3. For manual setup, create the three CNAMEs with the host names and values the page lists. SMTP2GO recommends a TTL of 14400 seconds.
4. At Cloudflare, set the records to DNS only and disable CNAME flattening, then click Verify. The domain works once its status reads Verified.
5. If it doesn't verify, check the CNAMEs on each of your authoritative DNS servers, or hover over the warning symbol on the Verified Senders page for the error.

DMARC alignment

With a verified sender domain, SMTP2GO signs with your domain. Without one, for example when you verify only a single sender address, it signs with its own DKIM signature and Gmail can show the mail as "via smtpcorp.com" or "via smtp2go.com". Single sender emails don't use your domain for SPF either, so they can't align for DMARC. Subdomains can send once the top-level domain is verified, provided they exist in your DNS.

Key length and rotation

The key sits behind dkim.smtp2go.net, a name SMTP2GO controls, so it can change the key without you touching DNS. SMTP2GO doesn't publish a key length or rotation schedule. Agencies can add their own CNAMEs pointing to dkim.smtp2go.net and give clients those names instead, as SMTP2GO's FAQ describes for return, DKIM and tracking records.

Common mistakes

• A DNS host that rejects underscores. The DKIM name needs one; SMTP2GO says to ask your host to add it manually.
• Cloudflare proxying or CNAME flattening. Both stop the records from verifying.
• Your domain appended to the value. Some hosts add it automatically; SMTP2GO's DNS guides say a trailing dot, as in dkim.smtp2go.net., stops that.
• Relying on a single sender address. Mail then carries SMTP2GO's signature, not yours.