How we make this list: we compare pricing pages, product documentation and public user reviews. Rankite is independent; if a vendor ever pays for a featured spot, that listing is clearly labeled Partner.
Quick comparison
| Tool | Best for | Starting price | Free plan |
|---|
 SendGrid | Teams that need transactional email and marketing campaigns in one platform | See website (flexible pricing, plan-based) | No (free trial, no credit card required) |
 Mailgun | Developers who want an API-first transactional email platform | See website | See website |
 Postmark | Transactional email where inbox placement and speed matter most | From $15/month (per vendor site) | No (free trial) |
 Amazon SES | High-volume senders already on AWS who want the lowest per-email cost | Pay-as-you-go per email (see vendor pricing page) | Yes (free usage tier, per AWS) |
 Brevo | SMBs that want an email API plus marketing automation in one account | See website | See website |
 Resend | Modern developer teams that want a clean, simple email API | From $0 (per vendor site) | Yes (free tier, per vendor site) |
 Mailtrap | Developers who need safe email testing before production sending | See website | See website |
 Loops | SaaS teams wanting marketing, product and transactional email in one platform | Free to start (per vendor site) | Yes (free to start, no credit card required) |
 MailerSend | Teams wanting transactional email with a free tier and clean tooling | Free plan (500 emails/month); paid from $5.60/month (Hobby, annual billing) | Yes (500 emails/month) |
Is your product missing or out of date?
We review this list regularly. Vendors can request a listing, send updated pricing or ask about featured placement.
Key takeaways
- For pure transactional delivery: Postmark (from $15/month) and Mailgun are the developer defaults; Amazon SES is the cheapest at high volume for AWS shops, with pay-as-you-go pricing and a free tier.
- For transactional plus marketing in one account: SendGrid (free trial, no card) and Brevo cover both without a second vendor.
- For modern developer experience: Resend (from $0) and Loops (free to start, no card) offer clean APIs and onboarding that older platforms cannot match.
- For pre-production safety: Mailtrap catches test emails before they ever reach real inboxes. MailerSend's free plan (500 emails/month) suits small projects.
The best email sending software
Your product already sends email: password resets, order confirmations, signup verifications, receipts. When those stop arriving, customers do not blame the inbox provider, they blame you. Email sending software exists so those messages get delivered, tracked and debugged through an API or SMTP relay instead of a shared host mail server. These nine tools cover the real options, from developer APIs to platforms that add marketing on top.
#1
SendGrid
Best for: Teams that need transactional email and marketing campaigns in one platform
Visit sendgrid.com
Starting priceSee website (flexible pricing, plan-based)
Free planNo (free trial, no credit card required)
SendGrid, now part of Twilio, is the established all-rounder: one account can send transactional email through the API or SMTP relay and run marketing campaigns with templates and automation. That combination suits teams that would otherwise pay for two vendors. The platform is proven at enormous scale, and the documentation and SDK coverage mean most stacks integrate in an afternoon. A free trial with no credit card required makes evaluation painless.
The pricing structure deserves attention before you commit. Transactional and marketing are separate subscriptions, so a team using both pays twice, and dedicated IPs cost extra. There is no permanent free tier, which rules it out for hobby projects. If you need both email types under one roof and can live with the subscription split, SendGrid remains the safe default.
What we like- Email API plus SMTP relay plus marketing campaigns in one account
- Proven deliverability at very large scale
- Extensive documentation and official client libraries
Watch out for- No permanent free tier
- Email API and Marketing Campaigns are separate subscriptions, which complicates pricing
#2
Mailgun
Best for: Developers who want an API-first transactional email platform
Visit mailgun.com
Starting priceSee website
Free planSee website
Mailgun is the developer's email API: REST and SMTP sending, inbound routing, suppression management, webhooks and detailed event logs, now with validation and deliverability suites alongside. It fits teams that treat email as infrastructure and want programmatic control over every part of it, including parsing incoming mail and validating addresses before sending.
The lineup has expanded well beyond simple sending, with Optimize, Validate and Inspect as separate concerns, so price the pieces you actually need rather than assuming one subscription covers everything. Check the current plans on mailgun.com before comparing. For API-first teams that want depth over simplicity, Mailgun is still one of the two names that come up first.
What we like- Built by developers for developers, with REST API and SMTP options
- Email validation and deliverability tooling alongside sending
- Inbound message routing included
Watch out for- Pricing and plan details need checking on the vendor site
- The product lineup has grown complex with separate Optimize, Validate and Inspect offerings
#3
Postmark
Best for: Transactional email where inbox placement and speed matter most
Visit postmarkapp.com
Starting priceFrom $15/month (per vendor site)
Free planNo (free trial)
Postmark built its name on one promise: transactional email delivered fast and placed in the inbox, not the spam folder. It keeps transactional and broadcast traffic on separate streams so a newsletter never harms password-reset deliverability, and the analytics show exactly what happened to every message. Teams that have been burned by promotional mail hurting transactional reputation appreciate that architecture. Pricing starts from $15 per month on the vendor site, with a free trial to test it.
The focus is also the limit. Postmark does not want to be your marketing platform; if you need newsletters and automation, pair it with something else. When the emails that must arrive are the whole job, Postmark is the specialist pick, and the entry price is clear enough to budget without a sales call.
What we like- Reputation for fast delivery and strong inbox placement on transactional mail
- Separate streams for transactional and broadcast email
- Detailed delivery analytics and webhook events
Watch out for- Strictly transactional focus, so marketing email needs another tool
- Paid from the start after the trial
#4
Amazon SES
Best for: High-volume senders already on AWS who want the lowest per-email cost
Visit aws.amazon.com
Starting pricePay-as-you-go per email (see vendor pricing page)
Free planYes (free usage tier, per AWS)
Amazon SES (Simple Email Service) is the cost leader for high-volume sending: pay per email with no subscription, running on AWS infrastructure, with a free usage tier to start. For a team already in AWS, it fits naturally with IAM permissions, VPC configuration and existing billing, and the price per thousand emails undercuts every dedicated platform at serious volume.
What you save in money you spend in effort. SES is infrastructure, not a product: the console is minimal, templates and analytics are basic, and deliverability monitoring, bounce handling and reputation management are largely your job. Teams with AWS expertise and high volume love it; everyone else should price their engineering time before calling it cheap.
What we like- Extremely low per-email pricing at scale
- Pay-as-you-go with no monthly commitment
- Integrates naturally with AWS infrastructure and IAM controls
Watch out for- Bare-bones console and tooling compared with dedicated email platforms
- Deliverability management, templates and analytics need more DIY effort
#5
Brevo
Best for: SMBs that want an email API plus marketing automation in one account
Visit brevo.com
Starting priceSee website
Free planSee website
Brevo, formerly Sendinblue, targets the small business that needs everything email in one place: transactional API, marketing campaigns, automation workflows and a lightweight CRM. It is the friendliest option here for teams without dedicated developers, with a visual campaign builder and automation recipes alongside the API. Being a European vendor, it leans into GDPR compliance as a selling point.
Developer experience is not the priority; API-first teams will find Resend or Mailgun cleaner. Pricing is tiered with sending limits, so check the current plans against your volume. For an SMB that wants one vendor for transactional mail, newsletters and basic automation, Brevo is the consolidated pick.
What we like- Combines transactional email API with marketing campaigns, automation and CRM features
- Approachable for non-developer teams
- European vendor with strong GDPR positioning
Watch out for- Less developer-focused than API-first tools
- Pricing tiers and limits need checking on the vendor site
#6
Resend
Best for: Modern developer teams that want a clean, simple email API
Visit resend.com
Starting priceFrom $0 (per vendor site)
Free planYes (free tier, per vendor site)
Resend is the modern answer to transactional email: a clean API, thoughtful documentation and React Email for building templates in code. Developers who found the older platforms clunky tend to reach for Resend first for new projects. Onboarding is fast, the dashboard is clear, and the vendor site prices from $0, so small projects start free. A test mode lets you simulate sending without risking real emails.
Youth is the trade-off. The feature set is narrower than SendGrid or Mailgun: fewer deliverability extras, fewer enterprise controls. Check the current paid plans on resend.com. For startups and product teams starting fresh, Resend's simplicity is the appeal; for complex enterprise needs, the incumbents still lead.
What we like- Clean, modern API design with excellent developer experience
- React-friendly email templating
- Test mode for safe experimentation
Watch out for- Younger platform with a smaller feature set than incumbents
- Paid tiers must be confirmed on the vendor site
#7
Mailtrap
Best for: Developers who need safe email testing before production sending
Visit mailtrap.io
Starting priceSee website
Free planSee website
Mailtrap solves the staging problem: during development, your app's emails go to a sandbox inbox instead of real customers, where you can inspect HTML, check spam scores and share previews with the team. It has since added production sending, so a team can test and send from one vendor. For agencies and product teams, the testing workflow alone justifies it.
As a production sender it is less battle-tested at high volume than the dedicated platforms, so verify the sending plans and limits before making it your primary. The honest use is hybrid: Mailtrap for every non-production environment, and either Mailtrap or a dedicated sender in production. Nobody wants a password reset going to a real user from a staging deploy.
What we like- Catches test emails in a sandbox so they never reach real recipients
- Email previews, spam scoring and HTML checks
- Production sending available alongside testing
Watch out for- Known primarily for testing, so production sending is less proven at scale
- Pricing for sending tiers needs verification
#8
Loops
Best for: SaaS teams wanting marketing, product and transactional email in one platform
Visit loops.so
Starting priceFree to start (per vendor site)
Free planYes (free to start, no credit card required)
Loops is the email platform built for SaaS teams: marketing campaigns, lifecycle workflows and transactional email in one place, with contacts kept in sync with product data. Deliverability safeguards are built in, with automatic bounce suppression, send pacing and manual review of sending. The vendor site says free to start with no credit card required, which makes trying it frictionless.
The positioning is deliberately narrow: SaaS companies sending lifecycle email. A publisher or ecommerce brand may find Brevo's marketing depth a better fit. Confirm the paid tiers on loops.so as volume grows. For a SaaS startup that wants one email vendor from waitlist to scale, Loops is the low-friction pick.
What we like- One platform for marketing, lifecycle and transactional email
- Built-in deliverability safeguards like bounce suppression and send pacing
- Free to start with no credit card
Watch out for- SaaS-focused, so less suited to non-software senders
- Paid tiers must be confirmed on the vendor site
#9
MailerSend
Best for: Teams wanting transactional email with a free tier and clean tooling
Visit mailersend.com
Starting priceFree plan (500 emails/month); paid from $5.60/month (Hobby, annual billing)
Free planYes (500 emails/month)
MailerSend is the newer developer-friendly option with the most transparent pricing on this list: a free plan with 500 emails per month, Hobby at $5.60 per month ($7 month-to-month) for 5,000 emails, Starter at $28 and Professional at $88, plus a 14-day Professional trial. The product covers transactional email via API or SMTP, with templates, inbound routing, email verification, scheduled sending and analytics in a clean dashboard.
Enterprise buyers will note it lacks the decade-long track record of SendGrid or Mailgun. But for teams choosing a transactional sender today who want modern tooling and honest pricing, MailerSend sits in the sweet spot between the newcomers and the incumbents, and the free tier makes it the easiest to try.
What we like- Free plan with 500 emails per month
- Clean API and SMTP relay with good documentation
- Inbound routing, templates, verification and analytics included
Watch out for- Less established than SendGrid or Mailgun at enterprise scale
- Higher tiers ($28 to $88/month) add up for heavy senders
How to pick email sending software
Start with the email type. Transactional email (receipts, resets, verifications) demands deliverability, speed and per-message tracking: Postmark, Mailgun, Resend, MailerSend and Amazon SES live here. Marketing email (newsletters, campaigns, automation) demands templates, lists and workflows: Brevo and SendGrid's marketing side live here. If you need both, either pick one vendor that does both (SendGrid, Brevo) or pair a transactional specialist with a marketing tool and keep the streams separate.
Then price your real volume, including growth. Per-email pricing (SES) wins at high volume; bundled plans win at low volume; free tiers win for side projects. Watch for the extras: dedicated IPs, email validation and advanced analytics are often separate line items. MailerSend publishes the clearest numbers here; for the quote-style vendors, confirm the free tier or trial terms on the vendor's site before you build on them, since these change.
Finally, test deliverability before you commit. Send to seed addresses at Gmail, Outlook and Yahoo, check placement, and review the bounce and complaint handling. Every vendor on this list offers a trial or free tier precisely for this. The API that is pleasant to integrate but lands in spam is worse than the clunky one that reaches the inbox.
How we chose
We started with the categories buyers search: email sending software, transactional email API and bulk email service. For each candidate we opened the vendor's own pricing page, checked prices against public reviews on G2 and Capterra and practitioner discussion on Reddit, and compared features, deliverability tooling, free tiers and company-size fit. Where a price could not be verified on the vendor's page we wrote "See website" rather than guessing.
Frequently asked questions
What is the difference between transactional and marketing email?
Transactional email is triggered by user actions: password resets, receipts, signup confirmations. Marketing email is bulk campaigns: newsletters, promotions. They have different deliverability requirements, which is why specialists like Postmark keep them on separate sending streams.
How much does email sending software cost?
It depends on volume. Amazon SES charges per email with no subscription, making it cheapest at high volume. MailerSend publishes plans from free (500 emails/month) to $88/month. Postmark starts from $15/month, Resend from $0, and Loops is free to start. Always model your monthly volume including growth before comparing.
Which email API is best for developers?
Mailgun and Resend are the developer favorites: Mailgun for depth (inbound routing, validation, webhooks) and Resend for a clean modern API. MailerSend sits between them with transparent pricing. Postmark wins when transactional inbox placement is the top priority.
Can I use one tool for transactional and marketing email?
Yes. SendGrid and Brevo both cover transactional sending and marketing campaigns in one account. The alternative is pairing a transactional specialist (Postmark, Resend) with a marketing tool, which keeps deliverability reputations separate. Loops covers marketing, lifecycle and transactional email for SaaS teams in one platform.
Do I need a dedicated IP address?
Only at consistent high volume, roughly 100,000-plus emails per month on a regular schedule. Below that, shared IPs from reputable vendors perform fine and warm up faster. Dedicated IPs cost extra at most vendors and require careful warmup. Resend offers managed dedicated IPs that warm up automatically.
How do I avoid the spam folder?
Use a dedicated subdomain for each email type, authenticate with SPF, DKIM and DMARC, keep lists clean, and separate transactional from marketing streams. Then monitor placement with seed addresses. The vendor matters less than these fundamentals, but Postmark and Mailgun provide the best tooling for them.
Sources we checked (11)
- https://sendgrid.com/
- https://mailgun.com/
- https://postmarkapp.com
- https://aws.amazon.com/ses/
- https://www.brevo.com
- https://resend.com
- https://mailtrap.io
- https://loops.so
- https://mailersend.com/
- https://www.g2.com/categories/email-deliverability
- https://www.capterra.com/transactional-email-software/
Is your product missing or out of date?
We review this list regularly. Vendors can request a listing, send updated pricing or ask about featured placement.
Shihab Mia · Founder, Rankite
Shihab has spent more than a decade helping SaaS and e-commerce brands grow through search. He writes Rankite's software buying guides from pricing pages, documentation and public user reviews. More about Shihab.