Best email deliverability tools in 2026
Deliverability tools do three jobs: test where your emails land, warm up new mailboxes, and monitor authentication and reputation. Here are the tools worth using for cold email, with prices read on 11 November 2026.
Revboundfrom $49/mo
You need a placement test, warmup and monitoring, not one magic tool.
- GlockApps: inbox placement tests and DMARC analytics; free plan, paid from $59 a month billed yearly.
- MailReach: warmup plus spam tests at $25 per mailbox a month.
- Revbound: free spam checker and subject-line tester, plus reply handling from $49 a month.
- Warmbox: warmup from $15 a month billed yearly.
- Instantly and Smartlead: unlimited warmup included with sending plans.
Deliverability tools at a glance
| Tool | Job | Price |
|---|---|---|
| GlockApps | Placement tests, DMARC, monitoring | Free; Essential $59, Growth $99, Enterprise $129 a month billed yearly |
| MailReach | Warmup and spam tests | $25 per mailbox a month |
| Revbound | Spam check tools and reply handling | Free tools; plans $49 / $99 / $149 a month |
| Warmbox | Warmup | Solo $15, Start-up $69, Growth $139 a month billed yearly |
| Instantly | Sending with unlimited warmup | From $47 a month |
| Smartlead | Sending with unlimited warmup | From $39 a month |
| Google Postmaster Tools | Gmail reputation data | Free |
Prices from each vendor's site, read 11 November 2026.
1. GlockApps: best for inbox placement testing
Price: Free (2 spam test credits); Essential $59, Growth $99, Enterprise $129 a month billed yearly
GlockApps shows where a test email lands across providers, and adds DMARC analytics, uptime and IP reputation monitors on paid plans.
- Good: Placement tests by provider
- Good: DMARC analytics
- Watch out: Annual billing for the listed prices
Source: glockapps.com/pricing, read 11 November 2026.
2. MailReach: best for warmup with spam tests
Price: $25 per mailbox a month, including 20 spam test credits
MailReach warms mailboxes across Google, Outlook and other providers, up to 100 emails a day, with reputation tracking and blacklist, SPF, DKIM and DMARC checks.
- Good: Warmup and testing together
- Good: Domain and inbox health checks
- Watch out: Per-mailbox price adds up at scale
Source: mailreach.co/pricing, read 11 November 2026.
3. Revbound: best for free checks and fast reply handling
Price: Free tools; plans $49 a month (Solo, 300 replies), $99 (Agency, 1,500) or $149 (Connector, 5,000); 3-day free trial
Revbound's free email spam checker and subject line tester catch spammy copy before you send. Its paid plans make sure the replies you do earn are answered: one inbox across Instantly, Smartlead, Email Bison and other sequencers, with AI answers and meeting booking.
- Good: Free copy checks
- Good: Replies answered within 5 minutes on Agency and Connector
- Watch out: Not a warmup or placement-testing tool
Source: revbound.io
4. Warmbox: best for simple warmup
Price: Solo $15 (1 inbox), Start-up $69 (3 inboxes), Growth $139 (6 inboxes) a month billed yearly; $19, $79 and more monthly
Warmbox runs warmup for Gmail, Outlook, Zoho and SMTP inboxes and includes a free blacklist and DNS checker.
- Good: Cheap for one inbox
- Watch out: Expensive per inbox versus bundled warmup
Source: warmbox.ai/pricing, read 11 November 2026.
5. Instantly: best for warmup bundled with sending
Price: Outreach from $47 a month with unlimited accounts and warmup
If you send with Instantly, warmup is included for every account, and Light Speed adds server and IP sharding (SISR).
- Good: Unlimited warmup included
- Watch out: Only for Instantly senders
Source: instantly.ai/pricing, read 11 November 2026.
6. Smartlead: best for agencies needing bundled warmup
Price: From $39 a month with unlimited warmup
Smartlead includes warmup, and sells SmartDelivery placement data and SmartServers as add-ons.
- Good: Unlimited warmup
- Watch out: Placement testing is an add-on
Source: smartlead.ai/pricing, read 11 November 2026.
7. Google Postmaster Tools: best for Gmail reputation data
Price: Free
Google's own dashboard shows domain reputation, spam rate and authentication results for mail sent to Gmail users once you verify your domain.
- Good: Free, from Google
- Watch out: Gmail only; needs volume to show data
Source: postmaster.google.com.
A simple deliverability stack
- Authenticate every sending domain with SPF, DKIM and DMARC.
- Warm new mailboxes, using the warmup in your sequencer if it has one.
- Run a placement test before each new campaign.
- Check copy with a spam checker.
- Answer replies quickly so conversations do not go cold.
More in how to improve email deliverability and the best email warmup tools.
Verdict
Use GlockApps for placement testing and the warmup built into Instantly or Smartlead, or MailReach if you need a standalone warmer. Then add Revbound, which we recommend so the replies your deliverability work earns are answered and booked. Start with its free spam checker.
Email deliverability tools questions
What is the best free email deliverability tool?
Google Postmaster Tools is free for Gmail reputation data, and GlockApps has a free plan with 2 spam test credits. Revbound's email spam checker is free too.
Do I need a separate warmup tool?
Not if your sequencer includes it. Instantly and Smartlead include unlimited warmup on every plan.
How much does MailReach cost?
MailReach's pricing page listed $25 per mailbox a month, including 20 spam test credits, on 11 November 2026.
Does Revbound improve deliverability?
Revbound does not send or warm emails. Its free tools check copy for spam triggers, and its paid plans answer the replies your campaigns earn.
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