SendGrid 403: from address does not match a verified Sender Identity Email / SMTP Origin: Network Last updated 4 Nov 2026

SendGrid: 403 Forbidden — The from address does not match a verified Sender Identity. Mail cannot be sent until this error is resolved

SendGrid only sends from addresses or domains you have verified (single sender or domain authentication).

Exact message you may see The from address does not match a verified Sender Identity403 Forbidden The from address does not match a verified Sender Identitysendgrid from address not verifiedMail cannot be sent until this error is resolvedSendGrid 403 Forbidden sender identity
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Seen on: SMTP

Meaning

Verify a Single Sender (click the email link) or authenticate your whole domain with the DNS records SendGrid gives you, then use a From address on that identity. API keys also need "Mail Send" permission, and free accounts may be held for review.

Common causes

  • From address not verified in Sender Authentication
  • Domain authentication DNS records not added or still pending
  • API key lacks Mail Send permission
  • From uses a different domain than the authenticated one
  • Account under review

⚡ Quick fix

  1. Settings → Sender Authentication → verify a single sender or the domain
  2. Use a From address on that identity
  3. Give the API key Mail Send access

Detailed fix by platform

curl

  1. Test the key: curl -s -o /dev/null -w "%{http_code} " https://api.sendgrid.com/v3/scopes -H "Authorization: Bearer $SENDGRID_API_KEY"

How to diagnose

  1. Identity — Sender or domain verified?
  2. DNS — Records published?
  3. Key — Mail Send permission?

🔧 Still not fixed?

Many errors look alike. If the steps above didn’t solve it, one of these is probably what you’re facing:

Where this error sits

Origin: Network. Errors that are often confused with or caused by this one (click to open):

421 4.7.0 Try again later (rate limited) — SMTP: 421 4.7.0 Our system has detected an unusual rate of unsolicited mail originating from your IP address. Mail sent from your IP address has been temporarily rate limited (Email / SMTP)421 4.7.0 Try again l…450 4.7.1 Greylisted, please try again later — SMTP: 450 4.7.1 <user@example.com>: Recipient address rejected: Greylisted, see http://postgrey.schweikert.ch/help/example.com.html (Email / SMTP)450 4.7.1 Greylisted,…451 4.3.0 Local error in processing — SMTP: 451 4.3.0 Error: queue file write error / 451 Requested action aborted: local error in processing (Email / SMTP)451 4.3.0 Local error…452 4.2.2 Mailbox full / over quota — SMTP: 452 4.2.2 The email account that you tried to reach is over quota (Email / SMTP)452 4.2.2 Mailbox ful…DMARC fail: SPF and DKIM not aligned — DMARC: dmarc=fail (p=REJECT) — SPF and DKIM pass but domains are not aligned with the From header (Email / SMTP)DMARC fail: SPF and D…Mailgun: Sandbox domains are for test purposes only — Mailgun: 403 Forbidden — Sandbox subdomains are for test purposes only. Please add your own domain or add the address to authorized recipients (Email / SMTP)Mailgun: Sandbox doma…SES: Maximum sending rate exceeded — Amazon SES: Throttling — Maximum sending rate exceeded (454 Throttling failure) (Email / SMTP)SES: Maximum sending …SendGrid …

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