SendGrid Alternatives: 7 Transactional Email APIs Compared

Direct answer. For most apps leaving SendGrid in 2026, the best alternative is AgentiSend: a free plan of 5,000 emails a month that does not expire, $16 for 50,000 emails and $28 for 100,000, 90 days of message history on Pro, and an idempotency key on every write. If price per message is the only number that matters and you will build your own logs, Amazon SES is the lowest.

SendGrid can still be the right home for a large team on its Pro or Premier plans. For a smaller team, three changes in SendGrid's plans matter directly: the free plan is gone, the entry plan keeps three days of history, and the dedicated IP comes bundled with a $89.95 plan.

What changed at SendGrid

Twilio's changelog dated 28 May 2025 says the free Email API and free Marketing Campaigns plans were retired, with a 60-day transition for accounts already on them. The Email API pricing page now shows a $0 column that lasts 60 days and allows 100 emails a day. After that, Essentials starts at $19.95 a month for 50,000 emails and Pro starts at $89.95 for 100,000 with one dedicated IP.

Two other details are worth checking before you renew:

• Short history on the entry plans. Searchable email activity is 3 days on the trial and on Essentials, and 7 days on Pro and Premier. More is an add-on.
• No idempotency key on send. The mail-send reference does not document one, so a timeout followed by a retry can deliver the same email twice unless you guard against it yourself.

Where these numbers come from

Nothing below comes from a send test of our own. Prices come from each provider's public pricing page, read 9 November 2026. Feature facts come from each provider's documentation, read between 28 September and 10 November 2026. Where a page did not say, we say so.

The comparison

The seven alternatives

1. AgentiSend

Best for: startups and product teams who want a free plan they can grow into, a lower bill than SendGrid at the same volume, and a modern API.

AgentiSend's free plan is 5,000 emails a month and 170 a day, with 3 domains and no card. Paid plans start at $9 a month for 30,000 emails. Pro is $16 for 50,000 and $28 for 100,000, and Scale runs from $72 for 100,000 to $920 for 2.5 million. Yearly billing takes 40% off any plan.

At 100,000 emails a month that is $28 against SendGrid's $34.95 on Essentials and $89.95 on Pro, with 90 days of searchable history instead of 3 or 7.

The parts SendGrid users notice first:

• Idempotency on every write, remembered for 7 days, so a retried request returns the first result instead of a second email.
• A batch endpoint that accepts or refuses each message on its own: up to 500 messages in one request, and one bad address costs one message, not the batch.
• Signed webhooks you can replay. A range of events can be re-sent on request, and a delivery that ran out of retries is listed instead of lost.
• Errors with a fix. A refused request carries a code, a message, the call that repairs it and whether retrying can help.
• Per-key send budgets and a kill switch that pauses every key in one request. This was built for AI agents, and it is just as useful for a cron job that misbehaves at 3 a.m.

Start free at agentisend.com. The guide for moving from another provider is at agentisend.com/docs.

2. Postmark

Best for: teams that want 45 days of activity history on every plan and SOC 2 listed on the pricing page.

Postmark's Basic plan runs $15 at 10,000 emails, $55 at 50,000 and $115 at 125,000. Pro adds inbound processing from $16.50. Its pricing page lists SOC 2 compliance and SMTP.

Watch out for: a 100-email free plan, no idempotency key and no HMAC-signed webhooks. At 100,000 emails it costs roughly three times AgentiSend.

3. Mailgun

Best for: teams who need SMTP and inbound routing, or a US and EU region from one account.

Mailgun charges $15 for 10,000 emails on Basic and $35 or $75 for 50,000 or 100,000 on Foundation. Scale, at $90 for 100,000, bundles a dedicated IP. Webhooks carry an HMAC-SHA256 signature.

Watch out for: log retention is 1 day on Free and Basic and 5 days on Foundation. You need Scale for 30 days.

4. Amazon SES

Best for: high-volume senders who live in AWS and will build the reporting themselves.

$0.10 per 1,000 on à la carte and $0.16 on Essentials, where new accounts start. Nothing on this list is cheaper per message.

Watch out for: no built-in message log, and no documented idempotency key on send. New accounts start in a sandbox limited to verified recipients, 200 messages a day and 1 a second; AWS gives a first response to a production-access request within 96 hours.

5. MailerSend

Best for: teams who want SMS and WhatsApp next to email on one account.

Starter is $35 for 50,000 and $68 for 100,000, with SMS included. Hobby is $7 for 5,000.

Watch out for: a 500-email free plan that asks for a card, and 1 day of activity on Free and Hobby.

6. Mailtrap

Best for: teams who want a test inbox that never delivers alongside production sending, and an audited provider.

The Email API free plan is 4,000 emails a month and 150 a day. Basic is $20 for 50,000 and $30 for 100,000. Every plan lists ISO 27001 and SOC 2 Type II. Email Sandbox is a separate product for test mail.

Watch out for: log retention is 3 days on Free and 5 on Basic, and the send endpoint does not document an idempotency key.

7. SMTP2GO

Best for: legacy apps, WordPress sites and devices that can only send through SMTP.

The free plan is 1,000 emails a month and 200 a day. $30 covers 50,000 and $75 covers 100,000 with a private IP. It offers data centres in the US, EU and Australia.

Watch out for: extra email past the plan is $1.00 to $1.20 per 1,000, and free accounts see 5 days of reporting.

Which one should you pick?

• You send from application code and want a permanent free plan, then the lowest bill on this list outside Amazon SES at 50,000 and 100,000 emails: AgentiSend.
• You want 45 days of activity history on the smallest paid plan: Postmark.
• You send millions a month and have engineers to spare: Amazon SES.
• You also need SMS: MailerSend.

Moving off SendGrid

1. Add your domain at the new provider and publish its SPF, DKIM and return-path records. Keep SendGrid's records until the switch is done; SPF can include both for a while.
2. Rewrite the send call. SendGrid's body nests recipients under personalizations; AgentiSend takes from, to, subject and html at the top level, so most calls get shorter.
3. Add an idempotency key derived from what the email is for (for example reset/<user id>/<token>), not from the time.
4. Re-point webhooks and move suppressions. Export your SendGrid bounce and unsubscribe lists and import them, so you do not re-mail addresses that already bounced.
5. Send a share of traffic for a few days, watch bounces, then move the rest.

Questions people ask

Does SendGrid still have a free plan? Not a permanent one for the Email API. The pricing page shows a 60-day trial at 100 emails a day.

What is the cheapest SendGrid alternative? Amazon SES per message. Among providers with a dashboard and logs included, AgentiSend is the lowest at 50,000 and 100,000 emails a month in this comparison.

Is there a SendGrid alternative with a permanent free plan? Yes. AgentiSend (5,000 a month), Mailtrap (4,000), SMTP2GO (1,000) and MailerSend (500) all have free plans with no time limit.

Sources

Pricing pages read 9 November 2026: twilio.com/en-us/products/email-api/pricing and the SendGrid pricing PDF, postmarkapp.com/pricing, mailgun.com/pricing, aws.amazon.com/ses/pricing, mailersend.com/pricing, docs.mailtrap.io (billing plans), smtp2go.com/pricing. SendGrid free plan change: twilio.com/en-us/changelog/changes-coming-to-sendgrid-s-free-plans. SendGrid send reference: twilio.com/docs/sendgrid/api-reference/mail-send/mail-send.