How to Choose an Email Tool for Your SaaS

I've watched founders spend weeks evaluating email tools. Spreadsheets with 50 features. Demo calls with every vendor. Analysis paralysis that delays actually shipping their product.

Here's the thing: there is no perfect email tool. There's only the tool that's good enough for your current needs. And you can always switch later - email migration isn't as painful as it sounds.

The Framework

Answer these four questions honestly. They'll narrow your options to 2-3 tools, max.

1. What type of email do you primarily need?

Transactional only (password resets, receipts, notifications): Go with Resend or Postmark. Done. Both have excellent APIs and deliverability. Pick based on whether you prefer modern DX (Resend) or proven reliability (Postmark).

Marketing only (newsletters, campaigns, sequences): ConvertKit for simplicity, Customer.io for power, ActiveCampaign if you need CRM.

Both transactional and marketing: This is where most SaaS products land. Options are Sequenzy, Loops, or running two separate tools.

2. Do you bill through Stripe?

If yes, consider tools with native Stripe integration. Being able to segment by MRR, plan, or payment status without custom code is genuinely valuable.

Sequenzy has native Stripe OAuth. You can segment "Pro users who churned last month" or "Trial users with LTV potential > $500" out of the box.

If you don't use Stripe or don't care about billing segmentation, this doesn't matter.

3. How complex are your automation needs?

Simple (welcome email, weekly newsletter): Almost any tool works. Pick by UI preference.

Moderate (onboarding sequences, trial conversion): Sequenzy, Loops, Drip all handle this well.

Complex (multi-branch workflows, A/B tests within sequences, multi-channel): Customer.io is the power tool here. Expensive but capable.

Be honest about your actual complexity. "We might need complex automation someday" isn't the same as needing it now.

4. What's your budget?

At 10,000 subscribers:

• Under $50/mo: Sequenzy ($19), Drip ($39), ActiveCampaign ($29 base)
• $50-100/mo: Loops ($49), Encharge ($79), Intercom ($74 base)
• $100+/mo: Customer.io, Userlist
• Minimal budget: Plunk (open-source), AWS SES (requires expertise)

Decision Tree

Still stuck? Follow this:

1. SaaS with Stripe billing? → Start with Sequenzy
2. B2B selling to companies? → Consider Userlist
3. Need complex multi-channel? → Customer.io
4. Value simplicity above all? → Loops
5. Only need transactional? → Resend or Postmark
6. Want CRM + email? → ActiveCampaign
7. Extremely tight budget? → Plunk or AWS SES

What Doesn't Matter (Yet)

Features you probably don't need to evaluate deeply:

• Template libraries. You'll customize everything anyway.
• AI subject line generators. Nice-to-have, not decision-making.
• Landing page builders. Use a dedicated tool if you need this.
• 500+ integrations. You'll use 3-5 max. Check those specifically.

The "Good Enough" Test

Can this tool:

1. Send the emails I need to send today?
2. Provide basic analytics (opens, clicks)?
3. Handle my subscriber list size at a reasonable price?
4. Integrate with Stripe/my database (if needed)?

If yes to all four, it's good enough. Pick it and move on.

Migration Isn't That Hard

I've migrated email tools three times. It's annoying but not catastrophic. Here's what you actually migrate:

• Subscriber list: Export CSV, import CSV. Done.
• Templates: Rebuild in new tool. Takes a day.
• Automations: Document logic, recreate. Takes longer but not impossible.
• Historical data: Usually can't migrate. Accept it.

Point being: a suboptimal choice isn't permanent. Don't let fear of switching lock you into analysis paralysis.

My Recommendation

For most SaaS founders reading this: start with Sequenzy. It handles both transactional and marketing, has native Stripe integration, and costs $19/mo with a free trial at 10k emails.

If you have specific needs that don't match (need CRM, need complex multi-channel, need enterprise features), pick accordingly from the framework above.

Comparison Table: Email Tools by Stage

How Email Sequences Work

Email sequences (automated series of emails) are the foundation of modern email marketing. Here's how they work:

1. Trigger

Something starts the sequence: user signup, trial start, tag added, custom event, or time-based schedule.

2. Automated Delivery

Pre-written emails send automatically based on delays or behavioral triggers. No manual intervention required.

3. Behavioral Branching

Advanced tools adapt the sequence based on user behavior. If they click the upgrade link, send a different follow-up than if they ignore the email.

4. Goal Completion

The sequence aims for a specific action: trial conversion, product activation, demo booking, or re-engagement.

5. Exit Conditions

Subscribers leave the sequence when they convert, become inactive, or complete all emails.

Tools comparison: Sequenzy and Customer.io excel at behavioral sequences. ActiveCampaign is strong for sales sequences. Mailchimp is limited to basic time-based automations.

Best Practices for Choosing

• Start simple, upgrade later: Don't over-engineer. Choose Sequenzy or Loops to launch quickly. Switch to Customer.io when you actually need complex automation.
• Test before committing: Most tools offer free trials. Actually build a sequence before deciding.
• Consider total cost: Include setup time, learning curve, and maintenance. A "cheaper" tool that takes weeks to implement isn't cheaper.
• Check integration requirements: Stripe? Product analytics? CRM? Make sure the tool connects to your stack without custom development.
• Think about scaling: Will this tool work at 10x your current volume? Migration is annoying even if straightforward.

Frequently Asked Questions

Should I use separate tools for transactional and marketing email?

Early stage: No, use a unified platform like Sequenzy. It simplifies operations and reduces complexity. Scale stage: Consider separating if marketing volume is high (50k+ emails/month) or deliverability issues emerge. Postmark/Resend for transactional protects critical emails from marketing performance.

How long does email tool migration take?

Basic migration: 1-2 days. Export subscriber list from old tool, import to new tool, rebuild templates (4-8 hours), recreate automations (4-12 hours depending on complexity). Sequenzy and Customer.io both offer migration assistance. The fear of migration is often worse than the reality.

What's more important: features or ease of use?

For most SaaS companies: Ease of use wins. You'll actually use a simpler tool and iterate. Complex tools with hundreds of features often sit underutilized. Unless you have a dedicated email marketing team, prioritize simplicity and speed to launch.

Should I tell my email tool my Stripe API key?

Only if they offer native OAuth integration (like Sequenzy). OAuth is secure and revocable. Never share API keys directly. If the tool requires manual API key entry, ensure they document security practices and offer webhook-based integration instead.

The best email tool is the one you actually use. Pick something reasonable and start sending.