Email Sending Services Comparison

📬 In brief: an email service is not "just any SMTP". Password reset and sending articles to 2,000 subscribers are two different tasks with different requirements. Below are 7 providers I have worked with or considered for clients, with prices as of October 2026 and advice on when to use each.

⚡ Key takeaways in 30 seconds

• ✅ Separate email types: transactional (password, confirmation, receipt) and marketing (articles, promotions, news) have different service requirements.
• ✅ Free plans are limited by daily quotas (100–300 emails per day) — they are not suitable for sending to your entire list.
• ✅ Cheapest for high volumes is Amazon SES ($0.10 per 1,000 emails), but it's the most complex to set up.
• ✅ For transactional emails, I look at Postmark and Resend, for no-code newsletters — at Brevo.
• ⚠️ Gmail SMTP — for testing only: 500 emails per day and risk of account blocking.
• ⚠️ Without SPF, DKIM, and DMARC, emails will go to spam with any provider.

📑 Article content:

• 📬 Transactional vs. Marketing Emails
• 📊 Comparison Table of 7 Services
• 🔍 Overview of Each Service
• 💰 How Much It Costs for Real-World Scenarios
• 🛡️ Deliverability: SPF, DKIM, DMARC
• 🎯 What to Choose for Your Task
• ❓ FAQ
• ✅ Conclusions

📬 Transactional vs. Marketing Emails

Over several years, I've integrated email into various projects, and the task has almost always boiled down to one of two types:

• Transactional — one email to one person in response to their action. Password reset in a project with authentication, registration confirmation, order receipt. Here, speed and inbox delivery are critical: if a password reset email arrives 10 minutes late or in spam, the user simply won't be able to log into their account.
• Marketing — one email to thousands of subscribers. Sending new articles from my blog, promotions, and new arrivals for a client with an online store. Here, bulk sending, templates, unsubscribe options, and statistics are important.

I recommend first determining exactly what you need the service for. Some providers are better suited for transactional emails, others for bulk newsletters, and some work effectively with both types. Therefore, I advise you to first assess your needs and then compare prices.

👉 What this means for you: if you have both types, keep them separate — at least on different subdomains (e.g., mail.site.com for transactional and news.site.com for newsletters). Complaints about newsletters will then not affect the delivery of password reset emails.

📊 Comparison Table of 7 Services

Prices are from official pages and verified reviews, as of October 2026. Tariffs change frequently, so check the provider's website before making a choice.

* For AWS accounts created after July 2025, the separate SES free tier has been replaced by general AWS credits.

🔍 Overview of Each Service

1. Resend

Currently, I am using Resend for sending new articles to blog subscribers. It's a young service, made "for developers": simple REST API, official SDKs, SMTP relay, webhooks, and templates on React Email.

Pricing: free for 3,000 emails per month, but no more than 100 per day. Pro — $20 for 50k, Scale — from $90 for 100k. Marketing campaigns are priced separately, by the number of contacts: free up to 1,000 contacts.

• ✅ Fastest start of all I've tried: domain, key, first email — in a few minutes
• ✅ Transactional emails and campaigns in one dashboard
• ✅ No unexpected bills on the free plan: sending simply stops when the limit is exceeded
• ❌ 100 emails per day limit on the free plan — you can't send to the entire base like this
• ❌ Different payment models for transactional emails and campaigns — you need to calculate both

When to choose: small and medium projects where email is integrated by a developer and API simplicity is important.

2. SendGrid (Twilio)

I used SendGrid before — it's one of the oldest and most well-known providers, now part of Twilio. Functionally very broad: API, SMTP, marketing campaigns, analytics.

Pricing: from 2025, there's no more permanent free plan — new accounts get a 60-day trial for 100 emails per day. Essentials — from $19.95 for 50k, Pro — from $89.95 with a dedicated IP.

• ✅ Mature product, many integrations and documentation
• ✅ Has both an API for transactional emails and a separate product for marketing campaigns
• ❌ Free — only a trial, from the 61st day a paid plan is required
• ❌ Interface and settings are more complex than newer services

When to choose: projects already in the Twilio ecosystem, or when a wide range of features is needed in one place. More details on choosing between it and Resend — in the article Resend vs SendGrid.

3. Amazon SES

AWS's sending service is the cheapest option for large volumes. Interesting fact: according to public data, some modern providers, including Resend, send emails through SES themselves.

Pricing: $0.10 per 1,000 emails, plus $0.12 per GB of attachments. Dedicated IP — separately.

• ✅ Lowest price: 100k emails — about $10
• ✅ AWS reliability and scale
• ❌ A new account starts in a "sandbox": sending only to verified addresses until a request for production access is submitted
• ❌ No convenient templates, editor, or subscriber management — it's a "pipe," you do everything else yourself

When to choose: large volumes (hundreds of thousands of emails), a team with AWS experience, or your own sending system on top of SES.

4. Postmark

Postmark is a specialist in transactional emails. Its main feature is separate streams (message streams) for transactional emails and campaigns, so they don't affect each other's reputation.

Pricing: free for 100 emails per month (for testing). Three plans from 10k emails: Basic $15, Pro $16.50, Platform $18 — the difference in price for exceeding the limit ($1.80 / $1.30 / $1.20 per 1,000).

• ✅ Reputation as one of the best for transactional email delivery
• ✅ Separation of transactional and bulk emails "out of the box"
• ❌ Expensive for volumes: 100k emails — about $126 even on the most favorable plan
• ❌ No intermediate plan between 100 and 10,000 emails

When to choose: password resets, confirmations, receipts — anything where an email "must arrive" and the volume is moderate.

5. Mailgun

Mailgun (now owned by Sinch, like Mailjet) is a popular service among developers with a powerful API. It stands out with built-in inbound email processing: user replies can be received via webhook.

Pricing: free for 100 emails per day. Basic — $15 for 10k, Foundation — $35 for 50k or $75 for 100k.

• ✅ Parsing incoming emails and address validation
• ✅ Flexible API and routing
• ❌ Free plan — for testing only
• ❌ Some features (templates, longer log storage) — only on higher plans

When to choose: when you need not only to send but also to receive email in your application.

6. Brevo (formerly Sendinblue)

Brevo is no longer a "developer API" but a marketing platform: visual email editor, segmentation, automations, SMS. The company is European, which is convenient from a GDPR perspective.

Pricing: free for 300 emails per day, but with the Brevo logo. Starter — from $9 for 5k emails, Standard with automations — from $18. Payment is per number of emails, not contacts.

• ✅ A marketer can assemble a campaign without a programmer
• ✅ Large contact base even on the free plan
• ❌ Brevo logo in emails on Free and Starter — removed for an extra charge
• ❌ For a developer, the API is less convenient than Resend or Postmark

When to choose: an online store or business where campaigns are done by non-developers — promotions, news, customer segments.

7. Gmail SMTP — why not for campaigns

At the start, I also sent emails via Google SMTP — it's free and configured in 5 minutes. But for production, and especially for campaigns, it's a bad choice:

• ❌ Daily limit: about 500 emails for regular Gmail and 2,000 for Google Workspace — and it's shared among all applications sending from that account
• ❌ Bulk sending from a personal account is a direct path to temporary sending blocking
• ❌ No delivery statistics, webhooks, unsubscribe, templates
• ✅ Suitable for local development, testing, and a feedback form on a business card website

💰 How Much It Costs in Real Scenarios

Here are three scenarios I've encountered myself or in client projects:

Scenario 1: blog, 2,000 subscribers, weekly newsletter

About 8,600 emails per month, but 2,000 at once. Here lies the main trap: free plans with daily limits (Resend — 100, Mailgun — 100, Brevo — 300, Gmail — 500) simply won't send the entire newsletter.

• Amazon SES — less than $1
• Postmark Basic or Mailgun Basic — $15
• SendGrid Essentials — $19.95
• Resend Pro — $20

Scenario 2: online store, 10,000 customers, 4 campaigns per month

Promotions and news — about 40,000 emails per month plus transactional order emails.

• Amazon SES — about $4
• SendGrid Essentials or Resend Pro — about $20 (fits within 50k)
• Mailgun Foundation — $35
• Postmark Platform — about $54 ($18 + 30k overage)

Scenario 3: service with authorization, up to 3,000 transactional emails per month

Password resets and registration confirmations. The volume is small, but each email is critical.

• Resend Free — $0, if not more than 100 emails per day
• Amazon SES — pennies
• Postmark Basic — $15, if delivery is more important than price

💡 My conclusion: there is no single best service — each is strong in its task. Postmark — for emails that must arrive, Brevo — for campaigns without a programmer, Resend — for quick integration into code, Amazon SES — for large volumes at minimal cost. For small volumes, the price difference is $10–20 per month, so choose based on the task, API convenience, and delivery quality, not the price list. For hundreds of thousands of emails, the difference is already several times — then the price becomes decisive.

🛡️ Deliverability: SPF, DKIM, DMARC

The most common reason why "emails go to spam" is not the provider, but an unconfigured domain. Any service from this list will ask you to add DNS records, and this is a mandatory step:

• SPF — allows the service to send emails on behalf of your domain
• DKIM — digital signature of the email
• DMARC — policy for emails that failed verification; minimum p=none

For bulk senders, Google and Yahoo have stricter requirements. If you send about 5,000 emails per day or more to personal mailboxes (gmail.com, yahoo.com):

• all three records are mandatory — SPF, DKIM, and DMARC
• in marketing emails — one-click unsubscribe (List-Unsubscribe-Post header per RFC 8058) and a visible unsubscribe link
• spam complaint rate — below 0.3%, and preferably below 0.1%

Spam rate and domain health can be tracked in Google Postmaster Tools.

👉 Practical advice: even if you are far from 5,000 emails per day, set up all three records and one-click unsubscribe immediately. Redoing it later, when the base grows and emails start bouncing, is significantly more expensive.

🎯 What to Choose for Your Task

How to connect any of these services to a Java application — via SMTP and JavaMailSender or via HTTP API — I will cover separately in the article Email Service Integration in Spring Boot: 8 Solutions to Prevent Emails from Getting Lost.

❓ FAQ

Can I send newsletters via Gmail SMTP?

For a few dozen emails – yes, for sending to a database – no. The limit is about 500 emails per day (2,000 in Workspace), and mass sending from a personal account can lead to sending being blocked.

Which service is the cheapest?

Amazon SES – $0.10 per 1,000 emails. But for a low price, you pay with setup time: sandbox, DNS, your own subscription and template logic.

Does a small website need SPF, DKIM, and DMARC?

Yes. SPF and DKIM are needed by any sender, and DMARC is mandatory for mass senders like Gmail and Yahoo. Without them, emails are much more likely to end up in spam.

Can I use one service for transactional emails and newsletters?

Yes – Resend, SendGrid, Postmark, and Brevo can handle both types. But keep them separate: separate streams or subdomains, so that newsletter complaints don't affect the delivery of important emails.

What happens if I exceed the free plan limit?

It depends on the service. With Resend on the free plan, sending simply stops until the next period, with no automatic charges. On paid plans of most services, exceeding the limit is charged at a separate rate.

✅ Conclusions

• First, determine the type of emails – transactional or marketing – and only then choose a service.
• Free plans are suitable for testing and transactional emails in small volumes, but not for sending to the entire database due to daily limits.
• For small volumes, the price difference between services is negligible – choose based on API convenience and delivery quality.
• For large volumes, Amazon SES is the most cost-effective if you are willing to spend time on setup.
• Set up SPF, DKIM, DMARC, and one-click unsubscribe from day one – this is more important than choosing a provider.

📚 Sources

• Resend — Pricing
• Twilio SendGrid — Pricing
• Amazon SES — Pricing
• Postmark — Pricing
• Mailgun — Pricing
• Brevo — Pricing
• Google — Gmail sending limits in Google Workspace
• Google — Email sender guidelines FAQ