Frequently asked questions
FAQ
Answers to common questions about Mailpipe, email configuration, and troubleshooting.
General
What is Mailpipe?
Mailpipe is a developer-focused email infrastructure platform. It gives you a programmable inbox — receive, send, and manage email via API, webhooks, and a modern web interface. Think of it as "your inbox, your database."
How is Mailpipe different from SendGrid or Resend?
Mailpipe is a full email client + API platform. While SendGrid and Resend focus on transactional sending, Mailpipe also handles receiving, storage, routing, and provides a Gmail-like web interface. You can actually use Resend, SendGrid, Postmark, or Mailgun as your sending provider under the hood.
What does it cost?
Mailpipe is $14/month for the standard plan, which includes 1,000 emails/day and full API access. See our pricing page for details.
Setup & Configuration
How do I set up my domain?
Add your domain in Settings → Domains, then configure DNS records (MX, SPF, DKIM). See our domains guide for step-by-step instructions.
How long does DNS propagation take?
DNS changes typically propagate within a few minutes, but can take up to 48 hours in rare cases. Most providers update within 5-30 minutes. You can check propagation status at dnschecker.org.
Which email providers are supported?
Mailpipe supports Resend, Postmark, SendGrid, and Mailgunas outbound email providers. Configure your provider in Settings → Domains → Provider.
Can I use multiple domains?
Yes! You can add multiple domains to a single organization. Each domain can have its own provider configuration and mailboxes.
API & Integration
What's the difference between live and test API keys?
mp_live_* keys send real emails and access production data. mp_test_*keys are for development — they validate requests but don't actually deliver emails.
Can I send emails from the web interface?
Yes! The compose modal in the inbox uses your Supabase session to authenticate. No API key needed for browser-based sending.
What are the rate limits?
Standard tier: 100 emails/hour, 1,000/day. Pro tier: 1,000/hour, 50,000/day. See Rate Limits for details.
Do you support webhooks?
Yes! Configure webhook endpoints to receive real-time notifications for email events (received, sent, bounced, opened). See our webhooks documentation.
Troubleshooting
My emails aren't being received
- Verify your MX records point to
mx.mailpipe.dev - Check that your domain is verified in Settings
- Ensure you have at least one mailbox created for the domain
- Check the routing rules aren't filtering the email
I'm getting 'Invalid key format' when sending
This means the API key doesn't match the expected mp_live_* or mp_test_*format. If you're using the web interface, make sure you're logged in — the compose modal uses your session token, not an API key.
Emails are going to spam
- Set up SPF, DKIM, and DMARC records for your domain
- Use a consistent "From" address
- Avoid spam trigger words in subject lines
- Include an unsubscribe link for marketing emails
- Warm up your domain by gradually increasing send volume
Still have questions?
We can help with anything from setup to scaling.