SparkPost SMTP settings: smtp.sparkpostmail.com, port 587, username SMTP_Injection

SparkPost SMTP relay: host smtp.sparkpostmail.com (EU: smtp.eu.sparkpostmail.com), ports 587/2525 STARTTLS, username literally SMTP_Injection and an API key with "Send via SMTP" as the password.

SparkPost (Bird) outgoing mail server: smtp.sparkpostmail.com, port <code>587</code> (STARTTLS) or <code>2525</code> (STARTTLS), username = SMTP_Injection (the literal string), password = an API key with the "Send via SMTP" permission.

SparkPost (Bird) SMTP settings at a glance

Outgoing (SMTP) hostsmtp.sparkpostmail.com (EU: smtp.eu.sparkpostmail.com)
Ports & encryption
587 — STARTTLS <em>(recommended)</em>
2525 — STARTTLS
UsernameSMTP_Injection (the literal string)
Passwordan API key with the "Send via SMTP" permission
AuthenticationCreate the key under Configuration → API Keys and tick Send via SMTP.

How to set up SparkPost (Bird) SMTP

  1. Configuration → Sending Domains → add and verify with DKIM.
  2. Configuration → API Keys → new key with Send via SMTP.
  3. App settings: host smtp.sparkpostmail.com, port 587, STARTTLS, username SMTP_Injection, password = key.

Sending limits

  • Free developer tier of about 500 emails per month; paid plans from about $20/month.
  • Sending domain must be verified with DKIM.

Things that catch people out

  • Port 465 is not offered.

Common SparkPost (Bird) SMTP errors

Server replyMeaningFix
535 5.7.8 Sorry.Key lacks Send via SMTP or wrong region.Create a key with the permission for your region.

More codes: 535 authentication failed, 550 relay denied, 554 rejected as spam, connection timed out — or all SMTP error codes.

When SparkPost (Bird) 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 SparkPost (Bird) now

Verified 2026-08-30 against SparkPost (Bird)'s documentation and live DNS. Found a change? Tell us.

SparkPost (Bird) SMTP — questions

smtp.sparkpostmail.com on port 587 or 2525 with STARTTLS; username SMTP_Injection and an API key as the password.