What email infrastructure do I need for a small SaaS?

For a small SaaS, you usually need two different email setups:

1. Transactional/product email — things like sign-up verification, password resets, receipts, alerts, onboarding, etc.
2. Business email — your team addresses like support@, billing@, founders@, etc.

1) Transactional email infrastructure

This is the most important part for a SaaS app.

You need:

• An email sending service (ESP)
  Use one of:

  • Postmark
  • SendGrid
  • Amazon SES
  • Mailgun
  • Resend

• A sending domain or subdomain

  • Best practice: send app email from something like mail.yourdomain.com or yourdomain.com
  • Example sender addresses:
    • no-reply@yourdomain.com
    • support@yourdomain.com
    • notifications@yourdomain.com

• DNS authentication records These are required for deliverability:

  • SPF
  • DKIM
  • DMARC

• Bounce/complaint handling Your provider should handle:

  • hard bounces
  • complaints/spam reports
  • suppression lists

• Webhooks or event tracking To know whether emails were:

  • sent
  • delivered
  • bounced
  • opened/clicked (optional, and increasingly unreliable due to privacy changes)

Good default choice

For a small SaaS, a very common setup is:

• Postmark for transactional email
• Send from mail.yourdomain.com
• Configure SPF + DKIM + DMARC
• Use webhooks for bounce handling

Postmark is popular because it’s simple and has strong deliverability.

2) Business email infrastructure

This is for humans, not the app.

You need:

• A domain email host like:
  • Google Workspace
  • Microsoft 365
  • Fastmail
  • Zoho Mail

Typical addresses:

• founders@yourdomain.com
• support@yourdomain.com
• billing@yourdomain.com

Why not use your app email provider for this?

Transactional providers are not ideal for normal inbox use. You want proper mailbox features, search, calendars, aliases, and day-to-day email handling.

3) Recommended minimal setup for a small SaaS

If you want the simplest practical stack:

• Domain registrar: Namecheap, Cloudflare, Porkbun, etc.
• Business email: Google Workspace or Fastmail
• Transactional email: Postmark or Resend
• DNS records: SPF, DKIM, DMARC
• A monitoring/logging setup: provider logs + webhooks
• Optional: separate subdomain for app email

4) Deliverability basics you should not skip

To avoid spam folders:

• Authenticate every sending domain
• Set up a DMARC policy, even if initially p=none
• Use a real From: address matching your domain
• Include plain-text versions of emails
• Avoid spammy wording and large image-heavy templates
• Keep bounce and complaint rates low
• Warm up gradually if you have lots of sends
• Separate transactional and marketing email streams

5) Marketing email is separate

If you later send newsletters/promos:

• Use a separate tool or separate sending domain/subdomain
• Examples:
  • Customer.io
  • Mailchimp
  • Brevo
  • HubSpot
  • Klaviyo

Don’t mix marketing with password resets and receipts if you can avoid it.

6) Small SaaS “starter pack”

A practical starter pack looks like:

• yourdomain.com registered at a registrar
• Google Workspace for @yourdomain.com
• Postmark for app emails
• DNS:
  • SPF
  • DKIM
  • DMARC
• Webhooks into your app for bounces/status
• Separate mail.yourdomain.com or notify.yourdomain.com for sending

If you want, I can also give you:

• a cheapest possible setup
• a best-practice setup
• or a step-by-step DNS/config checklist for a specific provider like Postmark, SES, or Resend.