How I Would Fix emails landing in spam in a Lovable plus Supabase AI chatbot product Using Launch Ready.

How I Would Fix emails landing in spam in a Lovable plus Supabase AI chatbot product Using Launch Ready

If your Lovable plus Supabase AI chatbot is sending emails that land in spam, I would treat it as a deliverability and trust problem first, not just an email-content problem. The most likely root cause is missing or misaligned sender authentication, usually SPF, DKIM, and DMARC, combined with a domain setup that was rushed during build.

The first thing I would inspect is the sending domain itself: DNS records, the exact "From" address, the mail provider account, and whether the app is sending from a custom domain or a free/shared one. In practice, spam placement often comes from a mismatch between what the user sees and what mailbox providers see behind the scenes.

Triage in the First Hour

I would start with a fast, ordered check so I do not waste time guessing.

1. Confirm which emails are failing.

• Transactional messages like signups, password resets, OTPs, chatbot follow-ups?
• Marketing or nurture emails?
• Internal notifications from Supabase edge functions or app backend?

2. Check the sending provider dashboard.

• Look for bounce rate, complaint rate, deferrals, and blocks.
• If you see 4xx or 5xx responses, note the exact SMTP error.

3. Inspect DNS for the sending domain.

• SPF record present and correct?
• DKIM enabled and signing?
• DMARC present with at least `p=none` to start?

4. Verify the "From", "Reply-To", and return-path alignment.

• The visible sender should match the authenticated domain as closely as possible.
• Avoid sending from random subdomains unless they are configured properly.

5. Check Supabase logs and function logs.

• Look for retries, timeouts, malformed headers, or failed API calls to the mail service.
• Confirm secrets are loaded correctly in production.

6. Review Lovable-generated email templates.

• Check for spammy subject lines.
• Check for broken HTML, too many images, missing plain-text fallback, or bad links.

7. Test with seed accounts.

• Send to Gmail, Outlook, and one EU mailbox if relevant.
• Compare inbox vs spam placement across providers.

8. Confirm domain reputation basics.

• Is this a new domain?
• Has it been used for cold outreach?
• Was it recently pointed through Cloudflare or another proxy without full mail DNS setup?

Root Causes

Here are the causes I see most often in AI-built products like this.

| Likely cause | How to confirm | Business impact | | --- | --- | --- | | SPF missing or wrong | Use DNS lookup and provider validation tool | Mailbox providers distrust your sender | | DKIM not signing | Check headers of a received email for `dkim=pass` | Messages look forged | | DMARC absent or too strict too early | Inspect `_dmarc` record and policy | Alignment failures trigger spam or rejection | | Shared or low-reputation sender domain | Test across Gmail/Outlook and check reputation tools | Deliverability stays unstable | | Bad email content/template structure | Review HTML, links, subject line, and plain-text part | Spam filters flag weak formatting | | App misconfiguration in Supabase/Lovable env vars | Compare staging vs production secrets | Emails fail silently or send from wrong identity |

How I confirm each one:

• SPF: I check whether the record includes only approved senders. Too many `include:` entries can break lookup limits.
• DKIM: I inspect message headers after delivery. If there is no `dkim=pass`, I do not trust the setup.
• DMARC: I verify that the policy exists and aligns with both SPF and DKIM domains. If there is no reporting address yet, that is still fixable later.
• Reputation: I test whether this is a fresh domain or one that has been used for outreach. New domains need warm-up discipline.
• Content: I compare inbox placement using stripped-down copy versus current copy. If plain transactional text lands better than branded HTML, content is part of the problem.
• Config: I compare local `.env`, Supabase project variables, deployment variables, and any third-party mail provider keys.

The Fix Plan

This is how I would repair it without creating a bigger mess.

1. Stop sending from an unverified identity.

• If you are using a free mailbox or unverified sender name/domain combo, pause sends until authentication is fixed.
• Do not keep burning reputation while testing.

2. Set up proper DNS authentication on the root domain or a dedicated subdomain.

• Add SPF for the actual mail service only.
• Enable DKIM signing in your mail provider.
• Add DMARC with `p=none` first so you can observe failures safely.

3. Separate transactional mail from anything promotional.

• Use one subdomain for product notifications if needed.
• Keep chatbot alerts and account emails distinct from marketing campaigns.

4. Fix headers and template quality.

• Use a stable `From` name like `Product Name <hello@yourdomain.com>`.
• Add plain-text alternatives to every HTML email.
• Remove spam-triggering language such as "urgent", "free", "act now", excessive punctuation, or all-caps subjects.

5. Verify environment variables in Supabase and deployment settings.

• Make sure production uses production keys only.
• Rotate any leaked or reused secrets immediately if they were exposed during testing.

6. Check Cloudflare only where it belongs.

• Cloudflare should manage web traffic and DNS records for web assets.
• Do not assume it fixes mail deliverability by itself; email authentication still depends on correct MX/SPF/DKIM/DMARC setup.

7. Re-test from clean accounts before turning traffic back on.

• Send to Gmail and Outlook seed addresses first.
• Only restore normal volume after inbox placement looks stable.

A small diagnostic command I often use before changing anything:

dig TXT yourdomain.com
dig TXT _dmarc.yourdomain.com
dig TXT selector._domainkey.yourdomain.com

If these records are missing or inconsistent with your provider docs, that is usually where the fix starts.

Regression Tests Before Redeploy

Before shipping any change back into production, I want proof that we did not break signups or alerting.

• Send test emails to at least 3 mailbox providers:
• Gmail
• Outlook/Hotmail
• One other real inbox used by your team
• Confirm inbox placement rate is at least 80 percent on test seeds before reopening traffic fully.
• Verify authentication results in message headers:
• SPF pass
• DKIM pass
• DMARC aligned
• Confirm links resolve correctly over HTTPS with no redirect loops.
• Check mobile rendering on iPhone and Android-sized screens if templates are user-facing.
• Validate that every critical email has:
• clear subject line
• plain-text fallback
• working unsubscribe link if promotional
• correct reply-to behavior if support-related
• Run a negative test:
• temporarily remove one bad config in staging only
• confirm monitoring catches it before production does

Acceptance criteria I would use:

• No bounce spike above 2 percent on test sends
• No spam placement above 20 percent on seed accounts during verification
• No broken links or image loads in major clients
• No secret leakage in logs
• No failed sends due to missing environment variables

Prevention

I would put guardrails in place so this does not recur after launch week chaos dies down.

• Monitoring:
• Track bounce rate, complaint rate, delivery latency, and provider-specific failures daily for two weeks after launch.
• Alert if bounce rate goes above 3 percent or complaint rate above 0.1 percent.

• Code review:
• Review all email-sending code paths before deploys.
• Check behavior first: sender identity, retry logic, error handling, header correctness.

• Security:
• Store API keys only in environment variables and secret managers.
• Rotate credentials after any contractor access or public demo exposure.
• Apply least privilege to mail provider roles when possible.

• UX:
• Tell users what kind of email they will receive after signup or chat completion.
• Provide fallback states if an email fails so users are not left waiting forever.

• Performance:
• Queue non-critical emails instead of sending them inline during user requests when latency matters more than immediate delivery.
• Keep p95 request latency low by moving slow mail calls off the critical path where possible.

For AI chatbot products specifically, I also watch for prompt-influenced content generation inside emails. If your bot can generate outbound copy dynamically without guardrails, you need checks against weird subject lines, unsafe links, accidental personal data inclusion, and unsupported claims before those messages ever leave your system.

When to Use Launch Ready

I built Launch Ready for exactly this kind of failure mode: something works in development but breaks trust at launch because domain setup, secrets, deployment hygiene, and monitoring were never finished properly.

• Domain setup
• Email authentication
• Cloudflare configuration
• SSL
• Deployment hardening
• Secrets cleanup
• Monitoring within 48 hours

That includes DNS fixes, redirects, subdomains if needed, Cloudflare setup where appropriate, SSL verification, caching, DDoS protection, SPF/DKIM/DMARC, production deployment, environment variables, secrets handling, uptime monitoring, and a handover checklist.

What you should prepare before booking: 1. Your domain registrar access 2. Cloudflare access if already connected 3. Supabase project access 4. Email provider access like Postmark, Resend, SendGrid, Mailgun as applicable 5. Deployment access for Lovable-connected hosting if relevant 6. A list of all current sender addresses and environments

If you want me to fix this quickly instead of guessing through another round of trial-and-error edits, book here: https://cal.com/cyprian-aarons/discovery

References

1. Roadmap.sh API Security Best Practices: https://roadmap.sh/api-security-best-practices 2. Roadmap.sh Cyber Security: https://roadmap.sh/cyber-security 3. Roadmap.sh QA: https://roadmap.sh/qa 4. Google Workspace Admin Help on SPF/DKIM/DMARC basics: https://support.google.com/a/topic/2752442 5. Cloudflare Email Routing docs: https://developers.cloudflare.com/email-routing/

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Take the next step

If this is a problem in your product right now, here is what to do next:

• [Use the free Cyprian tools](/tools) - estimate cost, score app risk, check launch readiness, or pick the right service sprint.

• [Book a discovery call](/contact) - I will tell you honestly whether you need a sprint or if you can DIY the next step.

*Written by Cyprian Tinashe Aarons - senior full-stack and AI engineer helping founders rescue, launch, automate, and scale AI-built products.*