Free Postmark alternatives: 6 apps ranked by verified data

Facts checked Nov 8, 2026AppBreakup editorialHow we rank

6 of the 8 Postmark alternatives we track can be used for free (free, open source, or with a free plan). Mailgun, Resend and Mailtrap rank highest, with facts last verified Nov 8, 2026.

Quick comparison

#	App	Pricing	Verified price	Open source	Platforms	Verified facts	Score
1	Mailgun	Free plan + paid	$35/month for 50,000 emails	No	Web	8 of 8	64.8
2	Resend	Free plan + paid	$20 a month for 50,000 emails (Pro)	No	Web	6 of 6	59.4
3	Mailtrap	Free plan + paid	$15/month for 10,000 emails	No	Web	4 of 4	57.5
4	Mailjet	Free plan + paid	$9 a month (Starter, 8,000 emails/month)	No	Web	6 of 6	52.6
5	Brevo	Free plan + paid	$9 a month for 5,000 emails	No	Web, iOS, Android	5 of 5	49.0
6	MailerSend	Free plan + paid	$68/month for 100,000 emails	No	Web	5 of 5	42.3

1. MailgunTop pick
Best for: Developers who need a reliable email API with inbound routing and address validation
Free plan + paidWeb
64.8
score / 100
Why switch from Postmark
Bigger free allowance per day plus an email validation API.
Pros
Permanent free plan with 100 emails a day
Inbound email parsing and routing to your app
Email validation API from the same vendor
Detailed logs and deliverability tooling
Cons
Free plan's daily limit only suits testing and tiny apps
Validation and extra emails are billed on top of the plan
No drag-and-drop marketing editor
Visit Mailgun Details and reviews
How this score is calculated
Editorial fit ×0.387
Reviews ×0.363
Clicks (90 days) ×0.150
Freshness ×0.15100
Votes ×0.150
0 counted reviews, 0 up and 0 down votes. Full formula
Is Mailgun a good Postmark alternative?
Verified facts
8 of 8 verified
Free plan
Yes, 100 emails/day
Checked Nov 8, 2026mailgun.com(opens source in a new tab)
Starting paid plan
$35/month for 50,000 emails
Checked Nov 8, 2026mailgun.com(opens source in a new tab)
Extra emails
From $1.80 per 1,000 (Basic)
Checked Nov 8, 2026mailgun.com(opens source in a new tab)
Customers
150,000+ businesses
Checked Nov 8, 2026mailgun.com(opens source in a new tab)
Starting price
$15/month for 10,000 emails (Basic)
Checked Nov 8, 2026mailgun.com(opens source in a new tab)
Foundation plan
$35/month for 50,000 emails
Checked Nov 8, 2026mailgun.com(opens source in a new tab)
Scale plan
$90/month for 100,000 emails
Checked Nov 8, 2026mailgun.com(opens source in a new tab)
Free trial
1 month (Foundation and Scale)
Checked Nov 8, 2026mailgun.com(opens source in a new tab)
2. Resend
Best for: Developers and startups who want a modern email API with React-based templates
Free plan + paidWeb
59.4
score / 100
Why switch from Postmark
Developer-first sending API with React Email templates, a newer take on Postmark's clean-API focus.
Pros
Simple REST API plus SMTP relay and official SDKs
React Email templates fit naturally into JavaScript codebases
Free plan is enough for side projects and testing
Transactional and broadcast email in one account
Cons
Free plan is capped at 100 emails a day
Dedicated IPs and SSO cost extra add-ons
Younger service with fewer marketing features than full email marketing suites
Visit Resend Details and reviews
How this score is calculated
Editorial fit ×0.369
Reviews ×0.363
Clicks (90 days) ×0.150
Freshness ×0.15100
Votes ×0.150
0 counted reviews, 0 up and 0 down votes. Full formula
Is Resend a good Postmark alternative?
Verified facts
6 of 6 verified
Free plan
Yes, 3,000 emails a month (100 a day)
Checked Nov 8, 2026resend.com(opens source in a new tab)
Starting price
$20 a month for 50,000 emails (Pro)
Checked Nov 8, 2026resend.com(opens source in a new tab)
Sending methods
REST API and SMTP relay
Checked Nov 8, 2026resend.com(opens source in a new tab)
Free trial
No, free-forever plan instead
Checked Nov 8, 2026resend.com(opens source in a new tab)
Dedicated IP
$30/month add-on
Checked Nov 8, 2026resend.com(opens source in a new tab)
Scale plan
$90 a month for 100,000 emails
Checked Nov 8, 2026resend.com(opens source in a new tab)
3. Mailtrap
Best for: Developers and QA teams who want email testing and transactional sending from one service
Free plan + paidWeb
57.5
score / 100
Why switch from Postmark
Pairs a sending API with an email testing sandbox, so you can preview messages before they reach real inboxes.
Pros
Sandbox catches staging email so real users never get test messages
Sending and testing in one account with shared templates
Free tiers for both sending and testing
Cons
Free sending plan keeps only 3 days of logs and allows 150 emails a day
Testing and sending are separate subscriptions
Dedicated IPs only on the higher sending tiers
Visit Mailtrap Details and reviews
How this score is calculated
Editorial fit ×0.363
Reviews ×0.363
Clicks (90 days) ×0.150
Freshness ×0.15100
Votes ×0.150
0 counted reviews, 0 up and 0 down votes. Full formula
Is Mailtrap a good Postmark alternative?
Verified facts
4 of 4 verified
Free plan
4,000 emails/month, 150/day
Checked Nov 8, 2026mailtrap.io(opens source in a new tab)
Starting price
$15/month for 10,000 emails
Checked Nov 8, 2026mailtrap.io(opens source in a new tab)
Email testing free plan
50 test emails, 1 sandbox
Checked Nov 8, 2026mailtrap.io(opens source in a new tab)
Sending methods
REST API and SMTP
Checked Nov 8, 2026mailtrap.io(opens source in a new tab)
4. Mailjet
Best for: Teams that need marketing and transactional email together, with collaborative editing
Free plan + paidWeb
52.6
score / 100
Why switch from Postmark
Pairs an email API with a visual editor if marketing email matters too.
Pros
Marketing and transactional email in one account
Real-time collaboration and approval workflows
Volume-based pricing with a free plan
Cons
Free plan has a daily send cap
Basic automation
Limited support on lower tiers
Visit Mailjet Details and reviews
How this score is calculated
Editorial fit ×0.346
Reviews ×0.363
Clicks (90 days) ×0.150
Freshness ×0.15100
Votes ×0.150
0 counted reviews, 0 up and 0 down votes. Full formula
Is Mailjet a good Postmark alternative?
Verified facts
6 of 6 verified
Free plan
Yes, 6,000 emails/month (200 per day)
Checked Nov 8, 2026mailjet.com(opens source in a new tab)
Free plan card
No credit card required
Checked Nov 8, 2026mailjet.com(opens source in a new tab)
Starter plan
8,000 emails/month, no daily limit
Checked Nov 8, 2026mailjet.com(opens source in a new tab)
Starting price
$9 a month (Starter, 8,000 emails/month)
Checked Nov 8, 2026mailjet.com(opens source in a new tab)
Essential plan
$19 a month, 15,000 emails/month
Checked Nov 8, 2026mailjet.com(opens source in a new tab)
Premium plan
$29 a month, 15,000 emails/month
Checked Nov 8, 2026mailjet.com(opens source in a new tab)
5. Brevo
Best for: Businesses with large contact lists that want email, SMS and a CRM in one place
Free plan + paidWeb, iOS, Android
49.0
score / 100
Why switch from Postmark
Puts transactional sending and marketing campaigns in one account, which Postmark keeps to a minimum.
Pros
Priced by emails sent, not contacts stored
Email, SMS, WhatsApp and transactional email together
Free plan with daily sending allowance
Cons
Free plan has a daily send limit and branding
Editor and templates less polished than some rivals
SMS credits cost extra
Visit Brevo Details and reviews
How this score is calculated
Editorial fit ×0.334
Reviews ×0.363
Clicks (90 days) ×0.150
Freshness ×0.15100
Votes ×0.150
0 counted reviews, 0 up and 0 down votes. Full formula
Is Brevo a good Postmark alternative?
Verified facts
5 of 5 verified
Free plan
Yes, up to 300 emails per day
Checked Nov 8, 2026brevo.com(opens source in a new tab)
Free plan terms
Free forever, no card needed
Checked Nov 8, 2026brevo.com(opens source in a new tab)
Starter volume
From 5,000 emails per month
Checked Nov 8, 2026brevo.com(opens source in a new tab)
Transactional messaging
Email, SMS and WhatsApp via SMTP and API
Checked Nov 8, 2026brevo.com(opens source in a new tab)
Starting price
$9 a month for 5,000 emails
Checked Nov 8, 2026brevo.com(opens source in a new tab)
6. MailerSend
Best for: SaaS and ecommerce teams who want an email API plus templates non-developers can edit
Free plan + paidWeb
42.3
score / 100
Why switch from Postmark
Free plan plus drag-and-drop templates that non-developers can edit.
Pros
Free plan for testing and small senders
Visual template editors alongside the API and SMTP relay
Built-in inbound routing, email verification and DMARC monitoring
Unused trial ends on the free plan, with no automatic charge
Cons
Free plan needs a credit card and has tight daily API limits
SMS sending only works in the US and Canada
Dedicated IPs are reserved for high-volume enterprise accounts
Visit MailerSend Details and reviews
How this score is calculated
Editorial fit ×0.312
Reviews ×0.363
Clicks (90 days) ×0.150
Freshness ×0.15100
Votes ×0.150
0 counted reviews, 0 up and 0 down votes. Full formula
Is MailerSend a good Postmark alternative?
Verified facts
5 of 5 verified
Free plan
500 emails/month
Checked Nov 8, 2026mailersend.com(opens source in a new tab)
Free trial
14 days of Professional
Checked Nov 8, 2026mailersend.com(opens source in a new tab)
Starter plan
$68/month for 100,000 emails
Checked Nov 8, 2026mailersend.com(opens source in a new tab)
Nonprofit discount
30%
Checked Nov 8, 2026mailersend.com(opens source in a new tab)
SMS coverage
USA and Canada only
Checked Nov 8, 2026mailersend.com(opens source in a new tab)

Quick comparison

1. MailgunTop pick

Pros

Cons

Verified facts

2. Resend

Pros

Cons

Verified facts

3. Mailtrap

Pros

Cons

Verified facts

4. Mailjet

Pros

Cons

Verified facts

5. Brevo

Pros

Cons

Verified facts

6. MailerSend

Pros

Cons

Verified facts