Hi everyone! I have a Salesforce Flow that sends confirmation emails. My Email Alert, Org-Wide Email Address, and email settings are configured correctly, but email delivery is intermittent: sometimes emails arrive, sometimes they don't.
I checked the Salesforce Email Logs, and failed messages show a DKIM authentication error (550-5.7.30).
Has anyone experienced this issue? How can I fix it? I appreciate your help.
I appreciate your help! Thank you!
#Flow #Email Deliverbility
Hi @Ariana Bayona,
Why it’s intermittent: If your Org-Wide Email Address is a Gmail or Yahoo address, Gmail’s DMARC policy tells receiving servers to reject mail with an @gmail.com From address that doesn’t come from Google’s own mail servers. Mail from Salesforce can’t be DKIM-signed for a domain you don’t own, so it gets through at some receivers and is rejected at others. A verified org-wide address only proves you own the mailbox. It doesn’t authenticate the domain. sage
Options without buying a domain:
- Use the substitute-address setting (best free fix). In Setup > Deliverability, enable “Use a substitute email address for unverified domains.” Salesforce then sends from a technical address in the form email@UniqueId.sfcustomeremail.com, using its own verified domain. Keep your real address as the Reply-To so replies still reach you. Check the exact setting name and location in your org. I haven’t confirmed where it sits in the current UI. salesforcebreak
- Send From a domain you already have access to. If you can use an address on a work or school domain, ask whoever manages that domain’s DNS to set up a DKIM key (Setup > DKIM Keys) or add it as an Authorized Email Domain.
- Buy a cheap domain. It’s roughly $10/year. Both DKIM keys and Authorized Email Domains require a domain you can add DNS records to, so there’s no free route to full authentication.
Check first: Open the failed messages in Email Logs and confirm which From address was used. Salesforce also now requires verified sending domains (from Spring ‘26, emails must come from a domain verified as belonging to your organization), so if your From is a free-mail address, this change could be part of why delivery became unreliable. If your From is not a free-mail address, tell me what it is and I’ll rework the diagnosis. salesforceben
Sources:
- Salesforce’s New Email Domain Verification Explained (Salesforce Ben)
- The Salesforce DKIM Sandbox Problem, and How to Fix It
- Email authentication for outgoing emails (Sage People)
I hope you find the above information helpful. If it does, please mark it as Best Answer to help others too.
