# Couryo blog

> Email that lands and sells: turning visits into relationships, deliverability without the mystery, transactional email in practice and honest tool comparisons.

- [Ads bring the visit. Email brings the customer home: rented vs owned audience](https://couryo.com/en/blog/rented-vs-owned-audience-email.md) (2026-10-20): Rented audience (social and ads) vs owned audience (your email list), with a worked example for your own numbers and how to start this week.
- [DMARC p=none vs quarantine vs reject: a safe rollout](https://couryo.com/en/blog/dmarc-none-quarantine-reject.md) (2026-10-20): What p=none, p=quarantine and p=reject do, the sp, np, pct and t tags, how to read an aggregate report and when to move up without losing legitimate email.
- [Does email marketing still work in 2026? What the data says](https://couryo.com/en/blog/does-email-marketing-still-work.md) (2026-10-20): Does email marketing still work in 2026? What the studies show (and what they don't), the common objections, and when email is not the right channel.
- [Email domain verification failed: how to fix it by DNS host](https://couryo.com/en/blog/email-domain-verification-failed.md) (2026-10-20): DKIM or SPF record not verifying? The 6 mistakes that block domain verification, how to spot each with dig, and the fix on Cloudflare, GoDaddy and more.
- [Email MCP server: how AI agents send and read email](https://couryo.com/en/blog/email-mcp-server-ai-agents.md) (2026-10-20): What MCP is, the 3 kinds of email MCP server, how to connect one to Claude Code, Cursor and Codex safely, and the prompts that pay off most.
- [Email provider suspended your account: what to do in the first 24 hours](https://couryo.com/en/blog/email-account-suspended.md) (2026-10-20): Your email provider suspended your account? Why it happens, an hour-by-hour plan for the first 24 hours and how to keep it from happening again.
- [Emails not reaching Outlook or Hotmail: the complete fix](https://couryo.com/en/blog/emails-not-reaching-outlook-hotmail.md) (2026-10-20): Why your emails are not reaching Outlook and Hotmail, Microsoft's May 2025 sender rules (550 5.7.515), every common 5.7.x code and how to get unblocked.
- [SaaS onboarding email sequence: day 0, 1, 3 and 7](https://couryo.com/en/blog/saas-onboarding-email-sequence.md) (2026-10-20): Build an event-triggered SaaS onboarding sequence: 5 emails with a goal and metric each, an exit when users activate, and the mistakes that cause spam.
- [SendGrid alternatives with a free tier (2026)](https://couryo.com/en/blog/sendgrid-alternatives-free-tier.md) (2026-10-20): SendGrid replaced its free plan with a 60-day trial. Compare Resend, Postmark, Mailgun, Brevo, Mailtrap and Couryo, with verified pricing.
- [Supabase email rate limit exceeded: the fix](https://couryo.com/en/blog/supabase-email-rate-limit.md) (2026-10-20): Getting email rate limit exceeded in Supabase Auth? The real limits, where to change them, how to set up custom SMTP and a production checklist.
- [Welcome email examples that work (and how to send them via API)](https://couryo.com/en/blog/welcome-email-examples.md) (2026-10-20): Five ready-to-copy welcome email examples (SaaS, store, course, app and B2B) with subject lines, preheaders and the code to send one at sign-up.