Should I run my own SMTP server?

Almost never. The cost is your time managing IP reputation, deliverability, bounce processing, and DKIM/SPF/DMARC. Even SES is usually wrong for under-100k volume; Postmark or Resend dominate on operational simplicity.

What about marketing email?

Mailchimp, ConvertKit, Customer.io, or HubSpot handle marketing email. Transactional services (Postmark, Resend) discourage marketing sending on transactional infrastructure — it ruins deliverability. Use separate services.

How do I improve deliverability?

1) Authenticate (SPF + DKIM + DMARC). 2) Warm the sending domain gradually. 3) Maintain low bounce + spam rates. 4) Use a dedicated subdomain (mail.yourdomain.com) so reputation issues don't affect your main domain. The service handles much of this, but understanding it matters for debugging.

Back to marketplace

Comparison · Email

Best transactional email services in 2026

Resend is the modern default for new startups. Postmark wins on deliverability and support. SendGrid is the legacy heavyweight. AWS SES is the cost-floor option for high-volume senders willing to manage their own deliverability. Pick by sender volume, technical comfort, and how much you care about not landing in spam folders.

Last updated June 16, 2026 · Editorial picks; no paid placement.

Who this is for

Founders setting up transactional email for the first time (signup confirmations, password resets, receipts) or migrating off a service that's stopped working.

Best overall

Resend

Best budget

AWS SES

Best for solo

Resend

Best for SaaS

Postmark

The tools

Resend

Free plan: Yes (3k/mo free) · From Free up to 3k emails/mo; $20/mo for 50k

Best for: Modern developer experience, React Email integration, founder-fit

Pros

· Best-in-class API + React Email templates
· Modern developer experience
· Strong deliverability defaults

Cons

· Newer player; fewer legacy integrations
· Smaller historical sender reputation
· Less mature reporting than SendGrid

Postmark

Free plan: 100 emails/mo (testing tier) · From $15/mo for 10k emails; volume tiers above

Best for: Deliverability-critical sends; transactional-only by design

Pros

· Highest deliverability rates in the category
· Separated transactional / marketing sending infrastructure
· Excellent support team
· Detailed bounce/spam reporting

Cons

· Pricier per-email than SES at volume
· Smaller integration ecosystem than SendGrid
· Less suited for marketing-heavy sending

SendGrid

Free plan: Yes (100/day) · From Free up to 100/day; paid $19.95/mo (40k emails)

Best for: Volume sending across both transactional and marketing

Pros

· Largest integration ecosystem
· Mature marketing + transactional combo
· Detailed analytics and reporting

Cons

· Deliverability has degraded vs Postmark over time
· Free tier is restrictive
· Twilio acquisition has slowed product velocity

AWS SES

Free plan: 62k emails/mo free from EC2 · From $0.10 per 1k emails (out of EC2); $1 per 1k otherwise

Best for: High-volume senders with technical depth to manage deliverability

Pros

· Cheapest per-email at scale
· Native AWS integration
· Production-grade infrastructure

Cons

· You manage deliverability — domain warming, IP reputation, bounce handling
· Sandbox restrictions until you request prod access
· No built-in template editor
· Sparse reporting compared to specialist services

Frequently asked questions

Should I run my own SMTP server?: Almost never. The cost is your time managing IP reputation, deliverability, bounce processing, and DKIM/SPF/DMARC. Even SES is usually wrong for under-100k volume; Postmark or Resend dominate on operational simplicity.
What about marketing email?: Mailchimp, ConvertKit, Customer.io, or HubSpot handle marketing email. Transactional services (Postmark, Resend) discourage marketing sending on transactional infrastructure — it ruins deliverability. Use separate services.
How do I improve deliverability?: 1) Authenticate (SPF + DKIM + DMARC). 2) Warm the sending domain gradually. 3) Maintain low bounce + spam rates. 4) Use a dedicated subdomain (mail.yourdomain.com) so reputation issues don't affect your main domain. The service handles much of this, but understanding it matters for debugging.

Next action

Open the Startup Operations hub

Operations for startups under 30 people: weekly review, monthly close, quarterly planning, and minimum-viable process that scales without strangling speed.

Open the Startup Operations hub

Editorial independence: Some marketplace links may be affiliate links. Editorial placement is not determined by commission. See our affiliate disclosure.

Related hubs

Startup Operations

Operations for startups under 30 people: weekly review, monthly close, quarterly planning, and minimum-viable process that scales without strangling speed.

Building a Devtools Business

Building API and developer-tools businesses: bottom-up adoption, docs as marketing, PLG pricing, and the unit economics of selling to engineers.