SendGrid SMTP settings: smtp.sendgrid.net, port 587, username apikey
SendGrid SMTP relay: host smtp.sendgrid.net, ports 25/587/2525 STARTTLS or 465 SSL, username literally "apikey" and your API key as the password. Sender verification, limits and the end of the free plan.
SendGrid outgoing mail server:
smtp.sendgrid.net, port <code>587</code> (STARTTLS) or <code>2525</code> (STARTTLS) or <code>25</code> (STARTTLS) or <code>465</code> (SSL/TLS), username = apikey (the literal word), password = an API key with "Mail Send" permission, created in Settings → API Keys.
SendGrid SMTP settings at a glance
| Outgoing (SMTP) host | smtp.sendgrid.net |
|---|---|
| Ports & encryption |
587 — STARTTLS <em>(recommended)</em>2525 — STARTTLS <em>(when 587 is blocked)</em>25 — STARTTLS465 — SSL/TLS |
| Username | apikey (the literal word) |
| Password | an API key with "Mail Send" permission, created in Settings → API Keys |
| Authentication | The username is always the string "apikey"; the API key is the password. Keys are shown once. |
How to set up SendGrid SMTP
- Settings → Sender Authentication → authenticate your domain (CNAMEs) or verify a single sender.
- Settings → API Keys → Create API Key → Restricted Access → Mail Send: Full.
- App settings: host smtp.sendgrid.net, port 587, STARTTLS, username apikey, password = the key.
Sending limits
- SendGrid retired its free plan in 2025 — new accounts get a 60-day trial, then paid plans (Essentials from around $20/month for 50,000 emails).
- Sender identity (single sender or authenticated domain) is required before sending; unauthenticated domains get low deliverability.
- Rate limits depend on plan; bounces/complaints suspend accounts.
Things that catch people out
- Trial accounts are limited to 100 emails/day and expire after 60 days.
Common SendGrid SMTP errors
| Server reply | Meaning | Fix |
|---|---|---|
535 Authentication failed: Bad username / password | Username is not "apikey" or key lacks Mail Send. | Use apikey + a Mail Send key. |
550 The from address does not match a verified Sender Identity | Sender not verified. | Verify the sender or domain. |
451 Maximum credits exceeded | Plan quota used. | Upgrade or wait for the reset. |
More codes: 535 authentication failed, 550 relay denied, 554 rejected as spam, connection timed out — or all SMTP error codes.
When SendGrid is not enough for your app
When a provider caps you or blocks a port, point the same app at QueenSMTP instead: host smtp.queensmtp.com, port 587 (STARTTLS) or 465 (SSL), your SMTP username and password from the dashboard. $5/year plus $0.10 per 1,000 emails, 100 free a day to test.
Get SMTP credentials — free to test Test SendGrid nowRelated settings
SendGrid SMTP — questions
smtp.sendgrid.net on port 587 (STARTTLS), 465 (SSL), 25 or 2525. Username is the literal string apikey and the password is a SendGrid API key.
Not any more: the free plan ended in 2025. New accounts get a 60-day trial, then a paid plan. A $5/year relay with $0.10 per 1,000 emails is the usual replacement for small senders.
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