SparkPost is a A transactional email is the automated message a WordPress site sends in response to a single user action – a password reset, an order confirmation, a form receipt – addressed to the user who triggered it. Read full reference → service that launched in 2011 as the cloud version of Message Systems’ Momentum MTA. MessageBird acquired it in 2022; MessageBird then rebranded to Bird in 2024. The product now lives inside Bird as its email offering, and Bird publishes SparkPost-branded pricing at 
bird.com/pricing/email?sp=true.
For WordPress sites evaluating email relay options in 2026: self-service signup is live, and Bird’s current card lists two paid tiers. Startup starts at $15/month for 50,000 emails and scales on a volume slider up to 100,000; Growth starts at $80/month for 100,000 and scales up to 2.5M. Overage above the plan’s included volume is $0.90 per 1,000 emails, capped by default at five times the plan quota. The free entry point is 1,000 emails per month. Dedicated IP, which used to be bundled into the top self-service tier, is now a $24.95/month add-on on Growth and above (up to five). Enterprise pricing is a direct quote for higher volumes. What has not returned is the WordPress plugin. The official SparkPost plugin was closed on WordPress.org in March 2025 for a security issue and has not been reinstated, so integration is via generic SMTP through a third-party mailer plugin.
SMTP settings (legacy)
The SparkPost SMTP endpoint remains documented and functional for existing accounts:
| Setting | Value |
|---|---|
| Host | smtp.sparkpostmail.com (US) or smtp.eu.sparkpostmail.com (EU) |
| Port | 587 (STARTTLS) or 2525 (alternate) |
| Encryption | STARTTLS required |
| Authentication | AUTH LOGIN |
| Username | SMTP_Injection (literal string, not your email) |
| Password | API key with “Send via SMTP” permission |
The username is always the literal string SMTP_Injection. The API key serves as the password. The WP mail config generator takes the literal SMTP_Injection username and the API key and returns a paste-ready block for WP Mail SMTP, FluentSMTP, or Post SMTP in “Other SMTP” mode.
Add SparkPost’s SPF and DKIM records to your domain’s DNS before sending production email. If the domain already carries a forwarding include or another sender in its SPF record, the SPF merger folds include:sparkpostmail.com into the existing string and counts the DNS lookups against RFC 7208’s ten-lookup ceiling. Once the records are live, the DNS auth checker reads SparkPost’s SPF include and DKIM selector the way receivers resolve them, so a stale nameserver or a mistyped selector shows up before real traffic does.
Acquisition timeline
| Date | Event |
|---|---|
| 2011 | SparkPost launched (cloud offering of Message Systems’ Momentum MTA) |
| 2016 | Free tier: 100K emails/month (made it popular with WordPress developers) |
| 2022 | Acquired by MessageBird |
| 2024 | MessageBird rebrands to Bird; SparkPost brand retired from product pages |
| March 2025 | Official WordPress plugin closed (reason: security issue) |
| July 2026 | Self-service tiers reintroduced under Bird: Starter ($20/mo) and Premier ($75/mo, dedicated IP included) |
| October 2026 | Starter and Premier replaced with Startup (from $15/mo, 50K) and Growth (from $80/mo, 100K); overage disclosed at $0.90/1,000; dedicated IP moved to a $24.95/mo add-on on Growth and above |
Pricing (verified 2026-10-04)
Bird publishes SparkPost pricing on a shared card at bird.com/pricing/email?sp=true. The card lists four tiers, with Startup and Growth driven by a monthly-volume slider:
| Tier | Monthly price | Included volume | What’s included |
|---|---|---|---|
| Free | $0 | 1,000 emails/month | Authentication, dashboards, suppression, webhooks, 30-day retention, shared sending IP |
| Startup | from $15 (50K) up to ~$30 (100K) | 50,000-100,000 emails/month | Same baseline as Free, scaled on the slider |
| Growth | from $80 (100K) up to ~$1,039 (2.5M) | 100,000-2.5M emails/month | Same baseline as Free; dedicated IP add-on eligible |
| Enterprise | Custom | 2.5M+ | Direct quote; account support included |
A few things worth flagging. The pricing card is now unusually explicit about what each dollar buys. Overage above the plan’s included volume is $0.90 per 1,000 emails on every tier, capped by default at five times the plan quota. Unused capacity does not roll over. The baseline feature set Bird lists on every paid plan is the same one it lists on Free – authentication, dashboards, suppression, webhooks, 30-day retention, and a shared sending IP – which makes the paid tiers primarily a volume ladder rather than a feature ladder.
Two things that used to be tier-gated have moved:
- Dedicated IP is a $24.95/month add-on, available on Growth and above, up to five IPs per account. It is no longer bundled with any base plan. A WordPress site that specifically wants a dedicated IP is paying Growth ($80/month) + add-on ($24.95/month) = $104.95/month minimum.
- Inbound email routing is no longer called out on the pricing card. SparkPost’s Relay Webhooks were the historical surface for inbound-parsed mail; Bird’s card does not surface tier gating for that feature. WordPress use cases that depend on parsed inbound (help-desk plugins, reply-to-post workflows) should confirm the tier that includes it directly with Bird before signing up.
The SMTP cost calculator plots SparkPost’s Startup and Growth entry prices against Postmark, SMTP2GO, Mailgun, and Amazon SES at whatever monthly volume the site actually sends.
Free tier
The free tier is permanent. 1,000 emails/month, via the same API and SMTP endpoint (smtp.sparkpostmail.com) that paid tiers use. Bird’s card does not state a credit-card requirement at signup either way; the SparkPost product page has historically launched new accounts without one, but confirm at the signup form.
The feature set at Free is the same baseline Bird lists for the paid plans: authentication, dashboards, suppression, webhooks, 30-day retention, shared sending IP. The dedicated-IP add-on is Growth-and-above only, so Free accounts are necessarily on Bird’s shared IP pool for deliverability.
The catch is smaller and quieter than the branded-footer or hard-daily-cap catches elsewhere in this comparison: 1,000/month divides to about 33/day if spread evenly, which is enough for a very low-volume site but tight for anything with occasional busy days. There is no documented daily rate limit inside the 1,000/month, so a burst that fits the monthly allowance is not artificially throttled.
The tier fits a small WordPress site sizing up SparkPost’s API and Signals analytics before deciding whether to move to Startup at $15, and any site whose monthly send volume genuinely stays under 1,000. It does not fit a site that needs a dedicated IP, which requires Growth plus the $24.95/month add-on.
WordPress integration (current state)
For the step-by-step install order (API key permission, sending-domain verification, the literal SMTP_Injection username most first-day setups miss, and the region selector), see SparkPost plugin for WordPress. The section below is the plugin-path overview; the how-to is the setup walk-through.
The official SparkPost WordPress plugin (last updated August 2023, tested up to WP 6.3.8) was permanently closed on the WordPress.org repository in March 2025 due to a security issue. It is no longer available for download.
For existing SparkPost users who still have valid API credentials, connection via a general mailer plugin remains possible:
| Plugin | Method | Notes |
|---|---|---|
| WP Mail SMTP | “Other SMTP” | Use SMTP settings above |
| FluentSMTP | “Other SMTP” | Manual SMTP configuration |
| Post SMTP | SMTP | Manual credentials |
No mailer plugin offers a dedicated SparkPost/Bird integration with OAuth or API-level features. Connection is SMTP-only via generic credentials.
Feature coverage
SparkPost’s capability set has held up through the acquisition and is roughly the same one that made it a peer of Mailgun and Postmark at its peak:
- Delivery webhooks (bounce, delivery, open, click, spam complaint) – listed as included on every plan
- Dedicated IP addresses – $24.95/month add-on on Growth and above (up to five IPs per account)
- Inbound email parsing via SparkPost Relay Webhooks – historical capability; current tier gating is not surfaced on Bird’s pricing card
- Template engine with Handlebars syntax
- Real-time delivery analytics (Signals)
- Email validation API
- Subaccount isolation – historically 15 at Premier; the current pricing card does not surface a tier-level cap
Bird’s current pricing card lists the same baseline features at every paid plan – the paid tiers are a volume and overage-ceiling ladder, not a feature ladder – which is a cleaner story than the Starter-vs-Premier gap under the earlier tier structure. Existing SparkPost accounts continue to use the same API surface and SMTP endpoint they always did.
Verdict
SparkPost is a viable option again for a WordPress site sending directly from WordPress. Self-service signup exists, the free tier gets a small site started, and the $15 Startup tier covers the shape of workload most WordPress operators are running at 50,000 emails a month (transactional email, shared IP, no inbound). The catch is the integration layer: the official plugin is still closed and Bird has not signalled a rebuild, so connection is generic SMTP through a mailer plugin rather than a dedicated Bird integration with OAuth or API-level features. That is workable, but it puts SparkPost a step behind Postmark, Brevo, and SendGrid on setup ergonomics for a WordPress operator picking a provider today.
When SparkPost fits. A site that wants the SparkPost API and Signals analytics at the newly-published $0.90-per-1,000 overage economics, is comfortable configuring generic SMTP, and either does not need a dedicated IP or is on Growth with the $24.95/month dedicated-IP add-on. Existing SparkPost accounts with working API credentials continue to run through the same SMTP endpoint.
When to look elsewhere. A site that needs a plugin-integrated experience with connect-in-two-clicks setup, or a low-volume site that specifically wants a dedicated IP without paying for 100,000 emails a month to unlock the add-on.
Alternatives worth comparing:
- SMTP2GO for the closest self-service equivalent with a generous free tier and simple setup.
- Postmark for deliverability-focused transactional email with a dedicated plugin.
- Mailgun for developers who want API-first infrastructure in the same general category.
For the broader setup that places SparkPost (or any provider) inside the WordPress email stack, see the WordPress email setup guide.
Corrections
- 2026-10-04. Pricing refreshed. Bird replaced the Starter ($20/mo) and Premier ($75/mo) tiers with Startup (from $15/mo at 50,000 emails) and Growth (from $80/mo at 100,000), both driven by a volume slider. The page now publishes an overage rate of $0.90 per 1,000 emails and a 5x default overage ceiling, and the dedicated IP moved from included-at-Premier to a $24.95/month add-on on Growth and above. Log retention is now stated as 30 days on all plans (previously documented historically at 10 days). Pricing section, lead, feature coverage, verdict, and acquisition timeline reworked.
- 2026-07-06. Pricing and framing refreshed. An earlier version of this page said SparkPost was enterprise-only and no longer available as a self-service product. Bird has since reintroduced self-service Starter ($20/mo) and Premier ($75/mo, dedicated IP included) tiers alongside a 1,000-emails/month free entry point. Verdict, lead, and pricing section rewritten to match.