If you're building a SaaS product, one of the most overlooked (yet critical) foundations is this: how you classify your emails.
Get this wrong and your emails may never reach your users. Worse? You could violate major regulations like CAN-SPAM, GDPR, or CCPA.
Here's your quick-start cheat sheet to email deliverability—the way I wish someone handed it to me when we first started shipping software.
Transactional vs. Marketing Emails: What's the Difference? 🔄
Not all emails are created equal. And email service providers (ESPs), privacy laws, and spam filters all treat them differently.
Let's break it down:
Transactional Emails (a.k.a. "Let the product work" emails) ✅
These are triggered by a user's action and are essential to your app's functionality. Think receipts, password resets, or subscription confirmations.
Common Examples:
- Password reset emails
- Purchase receipts
- Subscription or sign-up confirmations
- System alerts or notifications
Rules to follow:
- ❌ No opt-out/unsubscribe required
- ✅ Typically exempt from marketing laws (CAN-SPAM, GDPR), if strictly transactional
- ❌ Avoid adding promotions or marketing content to these—they'll lose their protected status
Marketing & Non-Transactional Emails (a.k.a. "The ones that get you in trouble") 📣
These are proactive. You're reaching out to promote, engage, or survey.
Common Examples:
- "We miss you" re-engagement emails
- Product updates and feature launches
- Onboarding drip sequences or tips
- NPS or satisfaction surveys
- Promotional offers or announcements
Rules to follow:
- ✅ Opt-out/unsubscribe link is required
- ✅ Must include your company name and physical mailing address
- ✅ GDPR/CCPA often require explicit opt-in, especially for European users
💡 Pro tip: If you're not sure if it's marketing, it probably is.
Pro Tips from the Email Trenches 🧠
Want to keep your deliverability rates sky-high and stay compliant? Here's what we've learned helping SaaS founders ship with confidence:
- Label emails properly in your ESP (Postmark, SendGrid, Mailgun, etc.) → Mislabeling = deliverability nightmares
- Use separate sending domains or IPs for transactional vs. marketing → Keeps your critical emails (like password resets) from being flagged
- Surveys are NOT always transactional → Unless they're triggered by user behavior (like after a cancellation), assume they're marketing
- Respect user preferences even if the law doesn't require it → Doing what's right builds trust and long-term retention
Quick Email Classification Guide ✅
| Email Type | Examples | Opt-Out Required? |
|---|---|---|
| Transactional | Password resets, receipts, alerts | ❌ No |
| Marketing | Promotions, product updates | ✅ Yes |
| Surveys | NPS, feedback requests | ✅ Yes (unless triggered by user action) |
Final Thoughts: Don't Let Emails Derail Your SaaS
Email classification might seem like a minor technicality—but if your users don't get critical messages (or worse, start marking them as spam), it's a huge hit to your product experience and trust.
At Eight Bit Studios, we've helped dozens of startups build smart, scalable communication systems from day one. Want a second set of eyes on your setup? Let's chat.