SendGrid is a deliverability-first sending platform that bolted inbound on as a secondary feature. MailKite treats inbound and outbound as one primitive: clean JSON webhooks, one API key, one quota, unlimited domains free — and no enterprise plan required to receive email properly.
SendGrid is a deliverability heavyweight with a mature sending infrastructure, extensive IP pool management, and battle-tested at scale. For pure outbound volume it is hard to beat — the friction shows up when you need inbound, clean payloads, or a simple account model.
SendGrid bolted Inbound Parse onto a sending platform — multipart payloads, limited routing. MailKite was built inbound-first: clean JSON, HMAC signatures, threading, and auth results from day one.
SendGrid organises work into subusers and domain-specific plans. MailKite gives you unlimited domains on one account, one API key, one quota — no hierarchy to manage.
Inbound Parse delivers multipart fields you reassemble. MailKite gives you one JSON object with parsed text, HTML, threading, auth, and signed attachment URLs.
Start free, receive and send from one API. No need to buy a sending tier just to get inbound webhooks working properly.
| MailKite | SendGrid | |
|---|---|---|
| Inbound payload | Parsed JSON object | multipart/form-data fields |
| Send + receive in one API | Yes — shared quota | Sending-first; inbound is secondary |
| Subuser / domain management | None needed — unlimited, free | Subuser hierarchy, per-domain structure |
| HMAC-signed webhooks | Yes, every plan | Signed-event verification available |
| Free tier | 3,000 emails/mo, unlimited domains | 100/day, limited features |
| SDKs | 8 languages | 8 languages |
| Deliverability at scale | SPF/DKIM/DMARC aligned, Cloudflare network | Excellent dedicated IP pools |
Competitor capabilities change — we re-audit these tables regularly. Spot something out of date? Tell us and we'll fix it.
No multipart boundary parsing, no charset reconciliation, no manual header splitting — just event.from.address, event.subject, event.text, and signed attachment URLs.
POST /your-webhook
Content-Type: multipart/form-data; boundary=xYzZy
--xYzZy
Content-Disposition: form-data; name="from"
Ada <ada@example.com>
--xYzZy
Content-Disposition: form-data; name="subject"
Re: invoice #1042
--xYzZy
Content-Disposition: form-data; name="text"
Looks good — approved!
--xYzZy
Content-Disposition: form-data; name="attachment1"; filename="po.pdf"
Content-Type: application/pdf
%PDF-1.7 …binary…
--xYzZy-- (+ headers[], envelope, charsets to reconcile)POST /your-webhook Content-Type: application/json
x-mailkite-signature: t=…,v1=… (HMAC-SHA256 — verify locally)
{
"id": "msg_2Hk9…",
"type": "email.received",
"from": { "address": "ada@example.com" },
"to": [{ "address": "support@myapp.ai" }],
"subject": "Re: invoice #1042",
"text": "Looks good — approved!",
"html": "<p>Looks good — approved!</p>",
"threadId": "<a1b2c3@mail.example.com>",
"auth": { "spf": "pass", "dkim": "pass", "dmarc": "pass", "spam": "ham" },
"attachments": [
{ "filename": "po.pdf", "contentType": "application/pdf",
"size": 18213, "url": "https://api.mailkite.dev/att/2Hk9…/0?sig=…" }
]
}SendGrid prices on volume tiers and feature gates inbound behind higher plans. MailKite prices on one combined quota with domains always free.
Add our MX records (or use a managed subdomain to start immediately). No sending plan required to receive.
Delete the form-parsing middleware. Read the JSON body directly: event.from.address, event.subject, event.text, event.attachments[].
Verify x-mailkite-signature locally, then reply through the same send API — SPF/DKIM aligned to your domain.
If pure outbound deliverability at scale is your only concern, SendGrid is solid. The case to switch is when you also need inbound email, want clean JSON payloads, or are tired of the subuser/domain hierarchy and per-plan feature gating.
Absolutely — many teams start by moving just inbound. You can consolidate onto MailKite later since send and receive share the same quota.
SendGrid's free tier is 100 emails/day with limited features. MailKite's free tier is 3,000 emails/month (in + out combined) across unlimited domains, with full feature access.
Yes — see our focused comparison of <a href='/alternatives/sendgrid-inbound-parse' class='text-accent hover:text-text'>MailKite vs SendGrid Inbound Parse</a> for the inbound-specific details: payload format, threading, auth results, and code diff.
Point a domain, drop in a webhook URL, receive your first email. Unlimited domains, no credit card.