Resend has a compelling product offer with a straightforward API, good documentation, and React Email from the same team. If you’re considering leaving Resend, pricing or plan limits may be the reason.
The free plan is capped at 100 emails a day. Past the monthly allowance, overage costs $0.90 per 1,000. A dedicated IP needs a Scale plan and at least 3,000 sends a day. Marketing email is a separate subscription priced by stored contacts. While the pricing doesn’t matter for users on the free tier, at 500,000 it’s the difference between $149 and $350.
We compared six APIs you could move to. Every price below comes from the vendor’s public pricing page, checked in September 2026. If a vendor has several ways to reach a volume, we used the cheapest one: base plan plus overage when that beats the next plan up.
Prices side by side
| Vendor | Free tier | 50,000 emails a month | Overage per 1,000 | Dedicated IP |
|---|---|---|---|---|
| Resend (for reference) | 3,000 a month, 100 a day | $20 | $0.90 | $30 a month, Scale only, 3,000+ sends a day |
| Mailfully | 5,000 a month, 200 a day | $19 | $0.40 | $29 add-on, included on Scale |
| Mailtrap | 4,000 a month, 150 a day | $20 on Basic | $0.88 on Basic | Included on Business ($85+) |
| Postmark | 100 a month | $55 | $1.80 on Basic | $50 per IP, Pro and up, 300,000 a month minimum |
| Mailgun | 100 a day | $35 | $1.30 on Foundation | Included on Scale ($90) |
| SendGrid | 60-day trial, no free plan | $19.95 | $1.30 on Essentials | Pro and up ($89.95+) |
| MailerSend | 500 a month | $35 on Starter | $1.30 on Starter | Not listed on the plans; ask sales |
1. Mailfully
Mailfully is a transactional email API, priced to stay cheap as volume grows. This is the first time it showed in our comparison and it has impressed us.
The free tier is 5,000 emails a month with a 200-a-day cap. Paid plans are Starter at $19 for 50,000, Growth at $49 for 150,000, and Scale at $149 for 500,000. Overage is a flat $0.40 per 1,000 on every paid plan, compared with Resend’s $0.90.
Against Resend, by monthly volume:
| Monthly volume | Mailfully | Resend |
|---|---|---|
| 3,000 | $0 | $0 |
| 50,000 | $19 | $20 |
| 100,000 | $39 | $35 |
| 500,000 | $149 | $350 |
| 1,000,000 | $349 | $650 |
Resend wins at 100,000, where its $35 Pro tier beats Mailfully’s Starter plus 50,000 emails of overage. At 500,000 emails, Mailfully costs $201 less per month.
Mailfully also includes marketing and inbound email in the same plan. Marketing email draws from the same allowance as transactional mail. There’s no second plan priced by contacts. Receiving email is included on every plan, Free too. Mail can arrive at your own domain with a webhook and API. Test-mode sends go to the mailbox simulator and are never billed. A dedicated IP is a $29 add-on on any paid plan with no volume floor. Scale includes one.
Logs keep each message’s full history, down to the reply from the receiving mail server, for 30 days on Starter, 60 on Growth, and 90 on Scale. Paid plans include support from a person who will pull up a message and read the log with you.
Mailfully lacks single sign-on and a first-party React Email integration. You can still use React Email by rendering your templates to HTML and passing that to the API.
Both APIs accept from, to, subject, and html, so you can reuse those fields when switching. The Mailfully SDK returns a { data, error } result instead of throwing.
Best for: teams that like Resend’s developer experience and want to pay less for it, especially the free tier, low volumes and high volumes above 100,000 emails a month.
2. Mailtrap
Mailtrap started as an email testing tool: a fake inbox that catches mail from staging so it never reaches a customer. Sending came later. Both products now sit in one account.
The free sending plan is 4,000 emails a month with a 150-a-day cap, one domain, and three days of logs. Basic is $15 for 10,000, $20 for 50,000, and $30 for 100,000, with five domains and five days of logs. Overage on Basic is $0.88 per 1,000.
Business starts at $85 for 100,000 and reaches $300 for 500,000. It adds a dedicated IP, 15 days of logs, and 100 domains. Overage drops to $0.55 per 1,000. Thirty days of logs needs Enterprise, from $750 a month.
Basic retains logs for only five days, so a support question about last week’s receipt may arrive after its logs have expired.
Best for: teams already using Mailtrap’s sandbox for testing that send under 100,000 emails a month.
3. Postmark
Postmark separates transactional and broadcast mail into Message Streams on different IP ranges and retains 45 days of history on every plan.
It’s also the most expensive option here. The free tier is 100 emails a month, not a day, with overage disabled. Basic costs $15 for 10,000, $55 for 50,000, $115 for 125,000 and $245 for 300,000. Pro costs 10% more at each volume and Platform 20% more. Overage on Basic is $1.80 per 1,000. There’s no annual discount.
Basic excludes inbound email, dedicated IPs, and two-factor authentication. Dedicated IPs cost $50 each a month and need 300,000 sends a month. Postmark counts sandbox test messages and each CC and BCC address against your quota. Your workload may require a higher allowance than the raw send count suggests. ActiveCampaign has owned the company since May 2022.
At 500,000 emails a month, Postmark costs around $379.
Best for: teams that will pay a premium for Postmark’s track record and want physically separate IPs for broadcast mail.
4. Mailgun
Mailgun is one of the older email APIs, known for its inbound routing and SMTP support. The free tier is 100 emails a day.
Pricing climbs quickly. Basic is $15 for 10,000 with $1.80 per 1,000 overage. Foundation is $35 for 50,000 at $1.30 overage. Scale is $90 for 100,000 at $1.10 overage. It’s the first tier with a dedicated IP included. At 500,000 emails a month, Scale plus overage comes to about $530.
Log retention is the weak spot on the cheaper plans. Free and Basic keep one day of logs. Foundation keeps five. You need Scale for 30. If a customer writes in on Monday about a receipt that never arrived on Friday, a Basic account has nothing to show you.
Best for: teams that need mature inbound routing and are sending under 100,000 a month or are happy on Scale.
5. SendGrid
SendGrid now lives inside Twilio. The sendgrid.com site redirects to twilio.com. The free plan was retired in 2025. New accounts get a 60-day trial at 100 emails a day. After that, sending pauses unless you pay.
The paid entry point is competitive. Essentials is $19.95 for 50,000 and $34.95 for 100,000. Pro starts at $89.95 for 100,000. Overage runs from $1.30 per 1,000 on Essentials 50K down to $0.50 at high volume.
Essentials includes three days of Email Activity history; Pro includes seven. Thirty days needs a paid add-on. Twilio doesn’t publish its price. That add-on is also the only way to query activity over the API. The activity API allows 6 requests a minute. Dedicated IPs, subusers, SSO, and automated IP warm-up all start at Pro. Marketing email is a separate subscription priced by contacts.
Deliverability on SendGrid’s shared pools has also been uneven lately. Between August 14 and August 17, 2026, Microsoft 365 blocks rose 10 to 15% across all SendGrid IPs. A similar Microsoft delivery problem came back on September 4.
Best for: companies already on Twilio that want email on the same contract and are ready to buy Pro.
6. MailerSend
MailerSend comes from the team behind MailerLite and is built for transactional mail only. It has a drag-and-drop template builder. Marketers and support staff can edit receipt templates without deploying code. Its paid plans also bundle SMS credits for the US and Canada.
The free plan is 500 emails a month, enough for testing and not much else. Every paid plan starts with a 14-day trial of Professional features. Hobby is $7 a month for 5,000 emails and one domain, with one day of activity history and overage at $1.50 per 1,000. Starter is $35 for 50,000 emails, 10 domains, and five seats, with 7 days of history and overage at $1.30 per 1,000. Paying yearly saves 10%.
Professional costs $110 a month for the same 50,000 emails. The extra $75 over Starter buys 30 days of activity history, 7 days of API logs, a dedicated account manager, a deliverability consultation, and unlimited users and domains.
Best for: teams where marketers or support staff edit the templates and where 50,000 emails a month is the ceiling for a while.
How to choose
Compare prices at your current monthly volume. Under 3,000 emails a month, Resend’s free plan is fine, although there are more generous free tiers. Between 5,000 and 100,000, Mailfully, Mailtrap Basic, SendGrid Essentials, and Resend Pro all land within a few dollars of each other. At those volumes, log retention, dedicated IPs, and the price of marketing email decide it. For higher volumes, compare the total cost of the plan and any overage. Mailfully’s $0.40 is the lowest of any API here.
Check which plans include the features you expect to need. Inbound email, a dedicated IP, and more than a week of logs are what vendors most often put behind a higher tier. Postmark gates inbound and 2FA. SendGrid gates dedicated IPs. Mailtrap keeps its dedicated IP and 15-day logs for Business. MailerSend keeps 30-day history and unlimited domains for Professional. Mailgun requires Scale for 30-day log retention. Resend gates dedicated IPs behind both a plan and a volume floor.
Check whether sending continues when you exceed your allowance. Every paid plan here bills overage and keeps sending. Postmark’s free tier stops sending when you reach its allowance.
Switching from Resend
You don’t have to move everything at once. DKIM uses a separate selector for each provider. A domain can be verified with two services at the same time. Verify your domain with the new provider, move a low-stakes email such as a weekly digest, watch the logs for a few days, then move password resets and receipts.
Export your suppression list before the first send. Without it, addresses that already bounced get mailed again. If you use React Email, keep it: render to HTML and send the output. Update your API client and credentials, then check field mappings, error handling, and webhooks.
At 500,000 emails a month, Mailfully costs $149 compared with Resend’s $350. It also has a larger free allowance and accepts the same core message fields.
Pricing checked September 2026. Vendors change plans often. Remember to confirm current figures before you commit.
