Domain sends email but cannot receive it
`your domain` publishes an SPF record, so it sends mail — but it has no MX record, so nothing can deliver mail back to it.
Why it matters
`your domain` publishes an SPF record, so it sends mail — but it has no MX record, so nothing can deliver mail back to it. Replies to your transactional email fail, bounce notifications are lost so you never learn which addresses are dead, and the DMARC aggregate reports that tell you whether your domain is being spoofed have nowhere to go. Customers who simply hit reply get an error.
How ShipReady detects it
Email-authentication DNS records (DMARC / SPF). Almost every AI-built SaaS sends transactional email — password resets, magic links, receipts — through Resend, SendGrid or Postmark. Setting that up gets the mail delivered; it does not stop anyone else sending mail that claims to come from the same domain. Without a DMARC policy, a receiving server has no instruction to reject a forgery, so an attacker can send "reset your password" from the product's own domain and the message will land in the inbox looking authentic. This check is almost entirely DNS rather than HTTP — one exception is MTA-STS, whose policy is only half-published in DNS; the other half is a file fetched over HTTPS (see _check_mta_sts). Nearly everything else here is the most deterministic kind of check the scanner has: a record either exists or it does not, so there is no heuristic and no false-positive surface. The one place judgement is required is deciding WHICH domain to ask about — see _organizational_domain.
Detection is deterministic. ShipReady reports this only when it observes the condition directly, and prefers to miss a real problem over inventing one. Rule version 1.10.0.
How to fix it
This is the prompt ShipReady puts in your report — written to be pasted straight into Cursor, Claude Code, or whichever assistant built the app.
The domain your domain sends email but publishes no MX record, so it cannot receive any. Add MX records pointing at whoever should receive mail for the domain — your email provider (Google Workspace, Microsoft 365, Fastmail, Zoho) supplies the exact hostnames and priorities. If the domain genuinely should never receive mail, publish a null MX record ("0 .") to say so explicitly, which also stops senders queueing and retrying deliveries that can never succeed. At minimum you need a working mailbox for the address in your DMARC rua= tag, or you will never see your own authentication reports.Frequently asked questions
- What does "Domain sends email but cannot receive it" mean?
- `your domain` publishes an SPF record, so it sends mail — but it has no MX record, so nothing can deliver mail back to it.
- How serious is it?
- ShipReady rates this medium. Fix soon. Meaningfully weakens a defence or degrades how the site works.
- How do I fix it?
- Paste the fix prompt on this page into Cursor, Claude Code or your AI editor. It is the same prompt ShipReady puts in your report.
- Can I check my own site?
- Yes — ShipReady scans up to ten pages of any public site for free and reports this alongside every other check. The free report lists every issue it finds and shows full evidence and a fix prompt for the critical and high-severity ones; medium and low findings are counted and unlock on Pro.
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