Warming up
Transactional email API
Warmerly is a cheaper SendGrid alternative at most volumes for apps sending transactional email: $29 for 100,000 a month against $34.95 on SendGrid Essentials, and a free plan of 5,000 a month that doesn't end, where SendGrid's free tier is a 60-day trial. SendGrid is the better pick if you need SMTP, templates, event webhooks, marketing email in the same account or a dedicated IP included in the price, and its plan steps make it cheaper at a few volumes, such as 300,000 and 1.5 million a month.
SendGrid's free tier is a trial. Warmerly's is a plan you can stay on while your app is small.
emails a month, up to 200 a day. No end date, no card.
emails a day, for 60 days. Then a paid plan from $19.95 a month.
At these four volumes Warmerly costs less. The curve above is the fuller picture: SendGrid's plan steps make it cheaper at 300,000 and 1.5 million a month, and the two meet at 700,000.
| Emails a month | Warmerly | SendGrid |
|---|---|---|
| 10,000 | $15Starter | $19.95Essentials 50k |
| 50,000 | $15Starter | $19.95Essentials 50k |
| 100,000 | $29Growth | $34.95Essentials 100k |
| 500,000 | $279Scale 500k | $499Pro 700k |
List prices, monthly billing, USD: the cheapest published plan that includes that many emails, overage left out on both sides. SendGrid prices from sendgrid.com as of September 2026; check their site for current rates. Shaded cells are the cheaper side.
What each one does today. Where Warmerly says "not yet", it means it: those are on the roadmap, not built.
| Feature | Warmerly | SendGrid |
|---|---|---|
| API shape | REST, JSON over HTTPS, bearer key, Idempotency-Key header | REST v3 /mail/send with a personalizations array; bearer key |
| SMTP relay | Not yet (on the roadmap) | Yes |
| Delivery webhooks | Not yet. Read each email's delivery timeline from GET /emails/{id} | Event Webhook: 2 on Essentials, 5 on Pro |
| Templates | Not yet. You send your own HTML and text | Yes (dynamic templates) |
| Dedicated IP | $29/mo on Scale plans | 1 included on Pro and Premier |
| Suppression list | Automatic on hard bounce and spam complaint, shared with Warmerly outreach | Yes: bounce, spam report and unsubscribe lists |
| Free tier | 5,000 a month (200 a day), no time limit, no card | 100 a day for 60 days (a trial) |
| Log retention | Content 30 days; the email record and its delivery events are kept | Email activity: 3 days on Essentials, 7 on Pro |
| SDKs | None. One HTTP request from any language | Official libraries for C#, Go, Java, Node.js, PHP, Python and Ruby |
| Support | Email (support@warmerly.com), plus a 99.9% monthly uptime commitment with service credits | See sendgrid.com |
Honestly, in these cases we would stay with SendGrid.
Most of the work is DNS. The code change is small, but it is a change.
Add the domain, publish the three DKIM CNAMEs, the bounce MX and SPF records and a DMARC record it gives you. Your existing SendGrid CNAMEs can stay until you switch.
SendGrid nests recipients in personalizations[].to[].email. Warmerly takes to, cc and bcc as a string or a list of strings at the top level, up to 50 each.
content[{ type: "text/html" }] becomes html, text/plain becomes text, and from: { email, name } becomes one string: "Name <email>".
Dynamic templates and handlebars substitutions have no equivalent yet. Render the HTML in your app (most frameworks already can) and send the result.
tags is a flat object of your own labels, returned in the email log.
| SendGrid | Warmerly |
|---|---|
| personalizations[].to[].email | to |
| personalizations[].cc / bcc | cc / bcc |
| from: { email, name } | from: "Name <email>" |
| reply_to: { email } | reply_to |
| subject | subject |
| content[{ type: "text/html" }] | html |
| content[{ type: "text/plain" }] | text |
| headers | headers |
| categories, custom_args | tags |
| template_id + dynamic_template_data | render the HTML in your app |
At most volumes, yes, on list prices as of September 2026: for example $29 against $34.95 for 100,000 and $279 against $499 for 500,000. SendGrid's plan steps make it cheaper at some volumes, such as 300,000 ($249 against $279) and 1.5 million.
SendGrid's free tier is a 60-day trial of 100 emails a day. Warmerly's free plan is 5,000 emails a month (200 a day) with no time limit and no card.
No. A dedicated IP is a $29 a month add-on on Warmerly's Scale plans. Everyone else sends on shared SES infrastructure, with each workspace isolated in its own tenant so another sender's bounce rate can't pause yours.
No. It is for email a user triggered: resets, receipts, notifications. Keeping marketing and cold email off it is what protects its reputation.
Not yet. Sending is one HTTPS request, which any language can make. An SMTP relay is on the roadmap.
Create a free account, verify a sending domain and send a test from the dashboard. 5,000 emails a month free, no card.
