"Email marketing" splits into a few different tools, so the right answer depends on what you're sending. Here's how I'd break it down:
**If it's a newsletter / audience building**
- **Beehiiv** — free up to ~2,500 subscribers, good growth and monetization features. Strongest pick if the newsletter itself is part of the business.
- **Buttondown** — indie, very cheap, markdown-based, no bloat. Great if you just want to write and send.
- **Kit (formerly ConvertKit)** — more expensive but the best ecosystem for creators selling digital products.
- Avoid Substack unless you want their discovery network badly enough to give up 10% of paid subscription revenue permanently.
**If it's lifecycle/product emails for a SaaS**
- **Loops** — built for exactly this, generous free tier, handles both transactional and marketing. Most bootstrapped SaaS founders I'd point here first.
- **Resend** — if you're comfortable in code and want transactional plus simple broadcasts. Cheap, great developer experience.
- **Customer.io** — much more powerful behavioral segmentation, but overkill and overpriced until you have real revenue.
**If it's ecommerce**
- **Klaviyo** is the default for a reason (deep Shopify integration, revenue attribution). It gets expensive as your list grows.
- **Omnisend** is the cheaper alternative that covers 80% of it.
**If it's general small-business marketing**
- **MailerLite** — best value in the category. Free to 1,000 subscribers, clean automations, doesn't punish you as you grow. This is my default recommendation when someone doesn't fit neatly elsewhere.
- I'd skip Mailchimp. It's the name everyone knows, but pricing has gotten aggressive and you're paying for features a solo founder won't use.
**If it's cold outbound sales**
Completely different tool category — Instantly, Smartlead, or Lemlist. Never send cold email from your main platform or main domain; you'll wreck the deliverability of the emails your actual customers need to receive.
**A few things worth knowing regardless:**
- Pricing usually scales with list size, not sends. Before committing, look at what the platform costs at 5,000 and 25,000 subscribers, not just today.
- Check that you can export subscribers *and* your automation logic. Lists are portable; years of built-out sequences usually aren't.
- You'll probably need a separate transactional sender (password resets, receipts) — Postmark, Resend, or AWS SES. Some platforms cover both, most don't.
- CAN-SPAM basics: physical mailing address in the footer, working one-click unsubscribe, honored within 10 days. If you have any EU or Canadian subscribers, GDPR and CASL are stricter — get explicit consent rather than assuming.
Pricing and free tiers in this space change frequently, so verify current numbers before you commit.
If you tell me what you're actually building and roughly what you'd be sending, I can narrow this to one recommendation.