The Best SMTP Relay Services in 2026
We researched SMTP relay services from official websites, including pricing pages, plan tables, and product documentation. Rankings reflect each product’s core delivery job, value for money, and verified features such as sending limits, IP options, event webhooks, and message handling for applications and mail systems.
Our top picks
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Top ranked
Postmark#1 of 268.8/10A focused SMTP and API service for transactional email, streams, templates, and events.
Free plan
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Runner-up
Amazon SES#2 of 268.7/10A broad AWS email platform with low usage-based pricing and no permanent free plan.
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Top-ranked free plan
Mailjet#3 of 268.7/10A broad email platform pairing SMTP relay with campaigns, automation, and analytics.
Free plan · 30-day trial
Advertiser disclosure: iTechGuides is reader-supported. Vendors can pay for top positions in our rankings and for a place on other products' pages, and we may earn a commission when you click some links. Bought places stand at the number bought; this page and our disclosure say so. Paying vendors may get a fuller, more detailed review from our editors, and that review can change their score. How we rank.
The full ranking 26 tools, best first
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Best forTransactional teams needing streams and templates
A focused SMTP and API service for transactional email, streams, templates, and events.
8.8/10★★★★☆Visit Postmark -
Best forAWS-based teams needing low-cost scale
A broad AWS email platform with low usage-based pricing and no permanent free plan.
8.7/10★★★★☆Visit Amazon SES -
Best forTeams combining relay and email marketing
A broad email platform pairing SMTP relay with campaigns, automation, and analytics.
Free plan · 30-day trial Our Mailjet verdict → Visit MailjetFor vendors Sponsor this spot · #3 · $79/mo →8.7/10★★★★☆Visit Mailjet -
Best forMid-volume senders needing inbound parsing
A capable relay for mid-volume teams that need inbound email workflows.
8.5/10★★★★☆Visit SocketLabs -
Best forDevelopers wanting broad transactional-email coverage
A developer-focused SMTP and API service with inbound routing, webhooks, templates and analytics.
8.3/10★★★★☆Visit Maileroo -
Best forWordPress and commerce sites needing relay
A focused relay service for website and application email, starting at $5 per month billed annually.
- Event webhooks
8.1/10★★★★☆Visit SendLayer -
Best forTeams wanting a complete relay with a free tier
A complete transactional email relay with a permanent free tier and low-cost Pro plan.
- Inbound email parsing
- Subaccounts
- Event webhooks
7.8/10★★★★☆Visit AhaSend -
Best forSmall senders wanting inexpensive API and SMTP access
Affordable SMTP and API delivery with useful tracking, validation, and project controls.
- Subaccounts
- Event webhooks
7.7/10★★★★☆Visit UniOne -
Best forLarge enterprises running their own MTA
A self-managed MTA for enterprises that need control over high-volume email delivery.
- Event webhooks
7.6/10★★★★☆Visit PowerMTA -
Best forLow-cost senders needing basic relay and reporting
A low-cost SMTP/API service with campaigns, reporting, and plans up to 150,000 credits.
- Event webhooks
7.5/10★★★★☆Visit SMTPProvider -
Best forHigh-volume senders needing FTP batch delivery
A flexible relay for high-volume email, especially FTP-based batch workflows.
7.4/10★★★★☆Visit Doppler -
Best forBroadcast-focused teams with SMTP needs
A broadcast-focused email tool with SMTP, inbound receiving, and API access.
7.3/10★★★★☆Visit Resend -
Best forSenders prioritizing outbound threat protection
A security-focused SMTP relay for hosting providers, with a high starting price.
- Subaccounts
- Event webhooks
7.2/10★★★★☆Visit MailChannels -
Best forBasic authenticated SMTP users
A focused SMTP relay with validated senders, reporting, and annual message-based plans.
7.1/10★★★★☆Visit AuthSMTP -
Best forSmall teams needing affordable transactional email
A flexible transactional email service with a permanent free plan and broad event tooling.
7.0/10★★★★☆Visit Brevo -
Best forMarketing teams needing automation and integrations
A broad marketing platform with limited fit for dedicated SMTP relay needs.
6.9/10★★★☆☆Visit SendPulse -
Best forMarketing teams needing multichannel campaign tools
A broad marketing platform, but not a focused SMTP relay service.
6.8/10★★★☆☆Visit Mailchimp -
Best forDevelopers needing established email infrastructure
Developer-focused email delivery with SMTP, APIs, inbound routing, and delivery analytics.
6.6/10★★★☆☆Visit Mailgun -
Best forTeams needing inbound email and SDK coverage
A developer-focused relay with inbound email, webhooks, SDKs, and a free starting tier.
6.5/10★★★☆☆Visit Mailtrap -
Best forBudget-conscious transactional email developers
A budget-friendly relay with inbound routing, webhooks, templates, and verification.
6.3/10★★★☆☆Visit MailerSend -
Best forStraightforward SMTP relay at small volumes
A practical outbound SMTP relay with API access, tracking, webhooks, and a free plan.
6.0/10★★★☆☆Visit SMTP2GO -
Best forEnterprise developers needing subaccounts
A broad developer email service with SMTP relay, inbound parsing, webhooks and subaccounts.
6.0/10★★★☆☆Visit Netcore -
Best forLow-cost pay-as-you-go transactional sending
Low-cost pay-as-you-go SMTP and API delivery for transactional email.
5.5/10★★★☆☆Visit ZeptoMail -
Best forTeams needing marketing automation with SMTP
A flexible SMTP relay and email marketing platform with strong automation breadth.
5.3/10★★★☆☆Visit Elastic Email -
Best forDevelopers wanting API-first relay tooling
API-first transactional email with SMTP, inbound webhooks, and delivery events.
5.2/10★★★☆☆Visit MailPace -
Best forTeams that need SMS rather than email relay
A Microsoft SMS API service for two-way messaging, alerts, and delivery reporting.
5.2/10★★★☆☆Visit Microsoft
No tools match those filters.
Compare at a glance
| # | Tool | Free plan | Paid from | Monthly send limit | Score |
|---|---|---|---|---|---|
| 1 | Postmark | Yes | $15/mo | 10000 emails/mo | 8.8 |
| 2 | Amazon SES | No | $0.10/unit usage-based | 8.7 | |
| 3 | Mailjet | Yes | 8000 emails/mo | 8.7 | |
| 4 | SocketLabs | No | $39.95/mo | 40000 emails/mo | 8.5 |
| 5 | Maileroo | Yes | 8.3 | ||
| 6 | SendLayer | No | $5/mo | 1000 emails/mo | 8.1 |
| 7 | AhaSend | Yes | 25000 emails/mo | 7.8 | |
| 8 | UniOne | No | $6/mo | 6000 emails/mo | 7.7 |
| 9 | PowerMTA | 7.6 | |||
| 10 | SMTPProvider | No | 1000 emails/mo | 7.5 | |
| 11 | Doppler Transactional | No | $30/mo | 50000 emails/mo | 7.4 |
| 12 | Resend Broadcasts | Yes | $20/mo | 50000 emails/mo | 7.3 |
| 13 | MailChannels Outbound | No | $99.99/mo | 40000 emails/mo | 7.2 |
| 14 | AuthSMTP | No | $72/yr | 2000 emails/mo | 7.1 |
| 15 | Brevo Transactional Email | Yes | $9/mo | 5000 emails/mo | 7.0 |
| 16 | SendPulse | Yes | $9.60/mo | 6.9 | |
| 17 | Mailchimp | Yes | 5000 emails/mo | 6.8 | |
| 18 | Mailgun | Yes | 10000 emails/mo | 6.6 | |
| 19 | Mailtrap Email Sending | Yes | $15/mo | 10000 emails/mo | 6.5 |
| 20 | MailerSend | Yes | $7/mo | 5000 emails/mo | 6.3 |
| 21 | SMTP2GO | Yes | $10/mo | 10000 emails/mo | 6.0 |
| 22 | Netcore Email API | Yes | 6.0 | ||
| 23 | ZeptoMail | No | $2.50/unit usage-based | 5.5 | |
| 24 | Elastic Email | Yes | $29/mo | 37500 emails/mo | 5.3 |
| 25 | MailPace | 5.2 | |||
| 26 | Azure Communication Services SMS | No | $1/mo | 5.2 |
Head-to-head All 26 comparisons →
- Postmark vs Mailjet
- Postmark vs SocketLabs
- Postmark vs Maileroo
- Postmark vs SendLayer
- Postmark vs AhaSend
- Postmark vs UniOne
- Amazon SES vs SocketLabs
- Amazon SES vs Maileroo
- Amazon SES vs SendLayer
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How we rank SMTP relay services
Every tool on this page was researched by iTechGuides Editors from its official website — pricing pages, plan tables and product documentation. We rank on how well each one does this category's core job, what the free or entry plan includes, and where it falls short. Where we have enough verified facts, the score out of 10 is a rubric — job fit, value and how much we could verify — shown with its breakdown on every tool's page; a tool we have not verified enough to score yet shows its rank without a number. Scores are re-checked when a product changes its plans. Read the full editorial policy, or submit a tool we missed.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
Last updated · How we research and update