Overview
Sending is the job most developers arrive with. A transactional email service takes a message from your code over an API or SMTP relay and delivers it: a password reset, a receipt, a signup confirmation. The free plans differ mostly in volume and in how the cap is measured. Postmark gives 100 emails a month. MailerSend gives 500. Resend gives 3,000 a month with a limit of 100 a day, and Mailjet gives 6,000 a month with 200 a day. Mailtrap allows 4,000 a month and 150 a day, and Maileroo allows 3,000 outbound emails a month. A monthly figure that looks large can be throttled by a daily one, so read both before you plan a launch-day send.
What to look for in a free email tier
Forwarding and aliases solve the receiving side. If you own a domain and want hello@yourdomain to land in your normal inbox, a forwarding service does it without a mail server. ImprovMX free covers one domain with 25 aliases and forwards up to 500 emails a day. SimpleLogin works the other way round: it gives you 10 aliases and one mailbox, so you can sign up for a site with a throwaway address and turn it off when the spam starts. Neither one replaces a mailbox. They route mail to one you already have.
Verification and testing keep bad mail out of your pipeline. Verifalia checks whether an address exists and gives 25 free verifications a day. Credits reset at midnight GMT and do not carry over, so it suits a signup form better than a bulk list clean. Mailinator's free plan offers unlimited public inboxes with no sign-up. Anyone can read a public inbox, so use it for test messages and never for anything private. Mailtrap adds a sandbox that catches mail before it reaches a real customer.
Common gotchas in free email plans
When you compare free SMTP and free transactional email plans, look past the headline number. Check the cap per day, the number of sending domains, how long logs are kept, and whether a plan stops sending or bills you when you hit the limit. Postmark's free plan never expires, and it allows no overages, so sending stops at 100 emails until the next month. Resend keeps 30 days of data. Mailtrap keeps 3 days of logs. The email free tier that fits is the one whose limits match the way your app actually sends.
10 free email tiers compared
| Product | Type | Free tier includes | Est. value | Card required |
|---|---|---|---|---|
| ResendFTV 44 | Free tier | Access to a 3,000 emails per month quota. | $3.00 / month | Not stated |
| MailjetFTV 56 | Free tier | 6,000 emails per month with a 200 emails per day sending limit. | $6.00 / month | No |
| MailerooFTV 63 | Free tier | Up to 3,000 outbound emails per month. | $15 / month | No |
| PostmarkFTV 50 | Free tier | 100 emails per month. | $2.00 / month | No |
| MailerSendFTV 41 | Free tier | Access to 500 emails per month. | $3.00 / month | Not stated |
| MailtrapFTV 39 | Free tier | 4,000 emails per month sending limit. | $2.00 / month | Not stated |
| ImprovMXFTV 52 | Free tier | Forward up to 500 emails per day. | $3.00 / month | No |
| SimpleLoginFTV 39 | Free tier | 10 aliases | $2.00 / month | Not stated |
| VerifaliaFTV 50 | Free tier | Up to 25 email verifications per day. | $2.00 / month | No |
| MailinatorFTV 74 | Free tier | Unlimited public inboxes for temporary email testing. | $79 / month | No |
Best free email picks by use case
Best for: You need to send password resets and receipts from an app and want SMTP or an API.
3,000 emails a month at up to 100 a day, three sending domains and 30 days of data retention, with SMTP relay and an API on the free plan.
Best for: You send a larger monthly volume and want a free SMTP relay.
6,000 emails a month with a 200-a-day limit doubles Resend's monthly volume, and SMTP relay and webhooks are included.
Best for: You want mail sent to you@yourdomain to arrive in your existing inbox.
One domain, 25 aliases and up to 500 forwarded emails a day, with no mail server to run.
Best for: You need to catch test emails before they reach real users.
A sandbox for test mail sits next to a 4,000-a-month sending quota, so one login covers both testing and production sends.
Best for: You want to check that addresses on a signup form are real.
25 free verifications a day, with credits that reset at midnight GMT.
Frequently asked questions
Is there a free transactional email service?
Yes. Resend gives 3,000 emails a month with a 100-a-day limit. Mailjet gives 6,000 a month with 200 a day. Mailtrap gives 4,000 a month. Postmark gives 100 a month and never expires. MailerSend gives 500 a month.
Which free email services include SMTP?
Resend, Mailjet and Maileroo all list SMTP relay on their free plans, next to an API. Resend allows 3,000 emails a month, Mailjet 6,000 and Maileroo 3,000 outbound.
Can I forward email from my own domain for free?
Yes. ImprovMX's free plan covers one domain with 25 aliases and forwards up to 500 emails a day. It keeps a log of received mail for 7 days.
What does a free email tier usually limit?
The usual limits are emails per month, emails per day, the number of sending domains and how long logs are kept. Postmark also allows no overages, so sending stops when the 100-email monthly quota is used.
Are Mailinator inboxes private?
No. Mailinator's free plan gives unlimited public inboxes, and anyone who knows the inbox name can read it. Use them for test messages only.
How many emails can I verify for free?
Verifalia's free plan gives 25 email verifications a day. Unused credits expire at midnight GMT and do not accumulate.
