Email Deliverability Tools: Software, Services, and Platforms Compared
Email deliverability tools split into three jobs: they test where a message landed (seed tests), they monitor your authentication and reputation (DMARC, blacklists, Postmaster Tools), or they simulate engagement to warm a mailbox up. Almost none of them send your campaigns, so most are a line item on top of the sending platform you already pay for. Prices run from $0 for the mailbox providers' own dashboards to $19.50 per mailbox a month at MailReach, $59 to $129 a month at GlockApps, and $96 per mailbox a month at Folderly. Before you buy any of them, run the free checks: they diagnose most problems outright.
Every price on this page was read from the vendor's own pricing page in July 2026.
Last updated July 2026
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The three jobs deliverability tools do
Testing: where did this message land?
A seed test sends your message to a panel of test mailboxes across Gmail, Outlook, Yahoo and others, then reports whether it hit the inbox, the promotions tab, or spam. GlockApps and MailReach both sell this. It is genuinely useful for catching a content or authentication problem before you send to a real list.
Monitoring: is my authentication and reputation intact?
DMARC report analytics, blacklist checks, and reputation dashboards tell you when something breaks. GlockApps is the strongest of these, with DMARC message volumes running to millions on the higher tiers. The mailbox providers give you a version of this free through Postmaster Tools and SNDS.
Warm-up: build a sending history from nothing
A warm-up pool has mailboxes in a network open, reply to, and rescue each other's mail from the spam folder, so a brand-new inbox has an ordinary-looking history before its first real campaign. MailReach is the best known standalone. It is a real on-ramp, and it is also the most misunderstood product in the category.
What none of them do: send your campaigns
GlockApps, MailReach and Folderly are all bought on top of a sending tool. That matters for the math, because outbound teams add mailboxes to spread volume, and two of those three price per mailbox. The line item grows exactly as fast as the sending it is meant to protect.
A standalone deliverability tool vs a sending platform that handles it
This is the real decision most buyers are making, and it is not GlockApps vs MailReach. It is whether you need a second subscription at all.
| Feature | ColdMailer | Standalone deliverability tools |
|---|---|---|
| Sends your campaigns | Yes. Sequences, AI personalization per prospect, and the sending itself, from your own SMTP. | No. GlockApps, MailReach and Folderly all sit on top of a separate sending tool that you also pay for. |
| How it prices | Flat. $49 a month on Pro, month to month, with unlimited SMTP accounts. | Per mailbox at MailReach ($19.50) and Folderly ($96), or by tier and test credits at GlockApps ($59 to $129). |
| What happens when you add 10 mailboxes | Nothing. The price does not move and inbox rotation spreads the volume across them. | MailReach goes to $195 a month, Folderly to $960 a month. GlockApps caps sending accounts by tier (1, 1, 10, 20). |
| Warm-up | Included. New domains warm up automatically as part of the platform. | MailReach's core product. GlockApps and Folderly approach it differently, and Folderly sells it as managed maintenance. |
| DMARC forensics at scale | No. We are a sending platform, not a DMARC analytics suite. If you need deep DMARC reporting, buy GlockApps. | GlockApps is genuinely the best of these, with DMARC message allowances up to 12,000,000 on Enterprise. |
| Managed, hands-on reputation repair | No. We give you the infrastructure and the ramp, not a consultant. | Folderly's actual product, and the reason it costs what it costs. For a burned domain you cannot abandon, that is a fair trade. |
| Your true spam rate at Gmail | Read it in Google Postmaster Tools, free. No tool, ours included, can move that number for you. | Same. Vendor dashboards report their own signals, but Postmaster Tools is the source Google acts on. |
| Commitment | Free tier, then month to month. | GlockApps has a real free tier. MailReach showed a promotional discount, not a free trial. Folderly's headline price is quoted on a yearly commitment. |
We are not the right answer for every row here, and we have said so. If your problem is DMARC forensics, buy GlockApps. If it is a burned domain and no in-house skill, Folderly earns its price.
Email deliverability tools compared
Five options, including the two free first-party dashboards most teams skip. Prices were read from each vendor's own pricing page in July 2026 and change often, so check before you buy.
Last updated July 2026
| Tool | Best for | Sending model | Starts at |
|---|---|---|---|
| ColdMailer | Outbound teams who want sending, warm-up and inbox rotation in one flat-priced platform | Bring your own SMTP, unlimited mailboxes, native sending | Free, then $49/mo |
| Google Postmaster Tools + Microsoft SNDS | Everyone. Your actual spam rate and reputation at Gmail and Outlook, from the source | Monitoring only, does not send | $0 |
| MailReach | Warming new or burned mailboxes on a sending stack you cannot replace | Warm-up and spam testing, does not send | $19.50/mailbox/mo |
| GlockApps | Forensics: DMARC report analytics, multi-provider seed tests, blacklist and uptime monitoring | Diagnostics and monitoring, does not send | Free, then $59/mo |
| Folderly | Enterprises outsourcing ongoing sender-reputation maintenance, with budget to do it | Managed deliverability service, does not send | $96/mailbox/mo, billed yearly |
GlockApps: Free (2 spam tests), Essential $59/mo, Growth $99/mo, Enterprise $129/mo, 30% off annual. MailReach: All-In-One at $19.50 per mailbox per month, 20% off annual. Folderly: $96 per mailbox per month on an annual commitment, with a separate Inbox Insights tier free for 2 tests a month or $79/mo for 100. ColdMailer: Free (100 emails a month, 1 SMTP), Pro $49/mo, Enterprise $149/mo.
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Diagnose it in this order, before you buy anything
1. Fix authentication, because it is free and binary
Google's sender guidelines require SPF or DKIM and a TLS connection for every sender, and SPF, DKIM and DMARC together for bulk senders at 5,000 messages a day or more. Check the DNS records on your sending domain, then send yourself a message and read the Authentication-Results header. If it says fail, stop. Nothing else you measure matters yet.
2. Read your real reputation for $0
Google Postmaster Tools and Microsoft SNDS are first-party dashboards. They show your spam rate, which is the number Google says to keep under 0.3% and recommends keeping under 0.10%. That number comes from real recipients hitting report spam. No third-party tool changes it.
3. Run a seed test to see placement per provider
Now a spam test earns its keep. It shows you whether Gmail inboxed you while Outlook spam-foldered you, which usually points at content or a specific auth failure. GlockApps' free tier gives you two credits, which is enough for a one-off diagnosis.
4. Only then decide what to buy
If authentication was broken, you already fixed it for nothing. If the mailboxes are new, you need warm-up, which your sending platform may already include. If real people are marking you as spam, no product in this category will save you. That is a list and message problem.
The one number mailbox providers actually enforce on
Google publishes what it wants, and it is short. Every sender needs SPF or DKIM set up and needs to transmit over TLS. Bulk senders, meaning anyone sending 5,000 or more messages a day to Gmail, need SPF, DKIM and DMARC together, plus one-click unsubscribe on marketing mail. And every sender is told to keep the spam rate reported in Google Postmaster Tools below 0.3%, with Google explicitly recommending you stay under 0.10%.
Read that threshold again, because it decides how you should think about this whole category. The spam rate is generated by real recipients pressing report spam. It is not generated by seed mailboxes, and it is not generated by warm-up pools. It is the people you emailed, deciding whether they wanted the email.
Which means a seed test cannot lower it, a DMARC dashboard cannot lower it, and a warm-up network cannot lower it. Those tools can tell you that you have a problem, and they can tell you which DNS record is broken, and they can give a new mailbox a plausible history. None of them reaches into the inbox of someone who did not want your email and stops their thumb.
That is not a reason to skip the tools. It is a reason to know exactly what you are buying, and to fix the free things first. Our guide to improving cold email inbox placement works through the levers that actually move the spam rate.
The four real causes of a deliverability problem
In practice, almost every cold outreach deliverability problem is one of four things. Knowing which one you have tells you whether any tool on this page will help.
1. Broken or missing authentication
SPF, DKIM or DMARC is absent, misaligned, or points at the wrong sending host. This is the single most common cause and it is completely free to diagnose and fix. A monitoring tool will find it. So will reading one email header. Fix it in DNS, not with a subscription.
2. A list of people who never wanted the email
Bought lists, scraped lists, and lists that are simply badly targeted produce complaints, and complaints produce the spam rate that Google enforces on. Nothing in this category fixes this. Not one product. It is fixed by targeting a narrower audience and verifying the addresses before you send.
3. Too much volume, too fast, from a cold domain
A domain registered last month that starts sending hundreds of messages a day looks exactly like what a spammer does. This is the one problem warm-up genuinely addresses, and it is why a proper warm-up ramp matters. Ramp gradually and the problem does not occur.
4. A message so generic it reads as bulk
Filters and humans both notice. A message that could have been sent to ten thousand people gets treated like it was. This is a copy problem, and it is why personalizing each email against real prospect data is a deliverability tactic and not only a reply-rate tactic.
Standalone deliverability tools address cause one, monitor the fallout of causes two through four, and genuinely help with cause three. They cannot fix causes two or four. That is the whole map of this market in one paragraph.
What email deliverability software costs in 2026
Three pricing models, and the difference between them matters more than the sticker price, because outbound teams add mailboxes on purpose.
Per mailbox. MailReach charges $19.50 per mailbox per month for its All-In-One plan (warm-up plus spam testing), with 20% off on annual billing. Folderly charges $96 per mailbox per month, quoted on a yearly commitment. Run twenty mailboxes to spread your sending, which is exactly what you are told to do, and MailReach is $390 a month while Folderly is $1,920 a month. The tool gets more expensive precisely as you follow best practice.
By tier and test credits. GlockApps runs Free (2 spam test credits, 1 sending account), Essential at $59 a month (360 credits, 1 sending account), Growth at $99 (1,080 credits, 10 sending accounts, 5 users) and Enterprise at $129 (1,800 credits, 20 sending accounts, 10 users), with 30% off annual. Its cost does not explode per mailbox, but its sending-account limits do gate you.
Free, from the source. Google Postmaster Tools and Microsoft SNDS cost nothing and report the reputation the mailbox providers themselves hold on you. Folderly's Pulse alerting is free too, and its Inbox Insights tier gives two placement tests a month at no cost. Use these. They are the most underused assets in the category.
Then there is the model we run: flat. ColdMailer is free to start (100 emails a month, one SMTP account), $49 a month on Pro, and $149 on Enterprise, with unlimited SMTP accounts and warm-up and rotation built into the sending platform rather than sold beside it.
When you genuinely need a standalone deliverability tool
We would rather be honest here than win the click, because you will find out either way.
Buy GlockApps if you need forensics. DMARC reports arrive as XML that nobody can read by hand, and GlockApps turns them into something legible at volumes up to twelve million messages on its top tier. If you have an unexplained placement drop, a blacklist you need to catch within the hour, or a compliance requirement to monitor authentication, that is a real job and this is a real tool for it. Its free tier is enough to diagnose a one-off problem. See our full breakdown of GlockApps pricing and alternatives.
Buy MailReach if you have new or damaged mailboxes and a sending platform you cannot or will not leave. Its warm-up engine is well regarded, it warms across Google and Outlook, and its assistant naming the specific broken record saves real time. The catch is the per-mailbox price. Our MailReach pricing and alternatives page runs the numbers at ten, twenty and fifty inboxes.
Buy Folderly if you are an enterprise with a burned domain you cannot abandon, a large mail program, or no in-house deliverability skill and a budget to outsource it. Managed maintenance with alerting is a legitimate product and some companies should buy it. Just go in knowing it is a yearly commitment at $96 per mailbox per month. We break that math down on the Folderly pricing and alternatives page.
Buy none of them if you are a founder, an agency, or a sales team doing ordinary cold outreach, your DNS is correct, and your mailboxes are warm. Run the free checks, read Postmaster Tools, and put the budget into a sending platform that handles the ramp for you. Most teams reading this page are in this group.
Where the sending platform does the deliverability work
The uncomfortable thing about this whole category is that the levers that actually move the spam rate live in the sending tool, not in the monitoring tool.
Volume ramp lives there. Inbox rotation lives there, because spreading a campaign across many mailboxes instead of hammering one is what keeps any single sender inside a normal-looking pattern. List verification lives there, because a hard bounce is a reputation event and the cheapest place to catch a dead address is before you send to it. And relevance lives there, because a personalized message is one nobody reports.
That is how ColdMailer is built. You bring your own SMTP, whether that is Google Workspace, Microsoft 365, SendGrid or Amazon SES, and connect as many accounts as you want on any plan. The platform rotates between them, warms new domains automatically, writes a genuinely different email for each prospect off their real data, and paces the sending instead of spiking it. You can read more about sending through your own SMTP relay and why owning the sending infrastructure changes your reputation position.
None of that makes a DMARC analytics suite unnecessary if you actually need DMARC analytics. It does mean most outbound teams are paying a per-mailbox subscription to watch a problem that better sending would have prevented. Run the free checks first and see which group you are in.
Who buys what in this market
Agencies running many client domains
Per-mailbox pricing is brutal here, because every client brings their own domains and inboxes. A flat-priced sending platform with unlimited SMTP accounts and built-in rotation keeps the deliverability cost from scaling with the client count. Use the free Postmaster Tools per client domain to prove inbox health in reporting.
Sales teams with a stack they cannot change
If procurement bought your sequencer and you are stuck with it, a bolt-on warm-up service is the pragmatic move. This is MailReach's core buyer, and it is a fair purchase. Price it at your real mailbox count before you sign, not at one.
Enterprises with a domain they cannot burn
When the sending domain is also the corporate domain, mistakes are expensive and outsourcing reputation maintenance to a managed service like Folderly is defensible. The yearly commitment is the price of somebody else owning the problem.
Founders and small teams starting outbound
You almost certainly do not need a second subscription. Set SPF, DKIM and DMARC correctly, open Postmaster Tools, warm the domain, keep the list tight, and spend the budget on the sending and the message instead.
Questions people ask about email deliverability tools
Put the deliverability budget into the sending, not beside it
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