# Email deliverability - explained plainly URL: https://www.inboxplease.com/learn InboxPlease Learn Practical guides on inbox placement, warmup, blacklist monitoring, and sender reputation — written for sales teams, founders, and developers who need their email to land in the inbox, not the spam folder. Email deliverability determines whether your emails reach the inbox or land in spam — and why. These guides cover the complete stack: warming a new sending domain to build sender reputation, running inbox placement tests to verify where mail actually lands across Gmail, Outlook, and Yahoo, monitoring blacklists to catch reputation problems before they compound, and repairing sender reputation when deliverability has already degraded. Written for sales teams sending cold outreach from dedicated domains, founders configuring transactional email, and developers building email infrastructure that needs to reliably reach the inbox. ## Warmup How email warm-up works, what goes wrong, and why your score might not reflect real inbox placement. - [How to warm up a new email domain](https://www.inboxplease.com/learn/how-to-warm-up-a-new-email-domain): A new domain has zero sending history. Before cold outreach can run at volume, you need 30 days of warmup. The right schedule, what to set up first, and the four mistakes that cause warmup to fail. - [Does email warmup actually work?](https://www.inboxplease.com/learn/does-email-warmup-work): Yes — when the seed network is made of real inboxes. Here is why network quality matters more than network size, and the question your current warmup tool probably cannot answer. - [Email warmup for cold outreach](https://www.inboxplease.com/learn/email-warmup-for-cold-outreach): Cold outreach from a new domain without warmup goes straight to spam. The right ramp schedule, the four mistakes that cause warmup to fail, and what to look for in a platform. - [Why your warmup score says 92 — and your campaign is still in spam](https://www.inboxplease.com/learn/warmup-score-spam): The score was accurate. The problem is what it was measuring against. How synthetic seed networks produce inflated scores, and what a real seed mailbox needs to provide a genuine trust signal. - [Can a warm-up tool get your domain blocked?](https://www.inboxplease.com/learn/can-a-warmup-tool-get-you-blocked): Four mechanisms that cause warm-up tools to harm the domain they are meant to protect: shared credential pools, excess inbox access, undisclosed network composition, and undifferentiated signup pools. What to check before you connect. ## Testing & monitoring How to measure inbox placement before you send, and catch blacklist listings before they affect delivery. - [Email deliverability tools — what to use and when](https://www.inboxplease.com/learn/email-deliverability-tools): Four categories of tools: inbox placement tests, authentication checkers, blacklist monitors, and warmup. What each does, when to reach for it, and a symptom-to-tool guide for common deliverability problems. - [How to test whether your emails land in the inbox or spam](https://www.inboxplease.com/learn/email-inbox-placement-test): An inbox placement test sends a real message to seed mailboxes and reports exactly where it arrived — per provider. Why open rates alone cannot tell you this, and what a full test checks. - [How to monitor if your sending domain is on an email blacklist](https://www.inboxplease.com/learn/email-blacklist-monitoring): A blacklist listing can block delivery silently within hours of a spam complaint. The major lists that affect real delivery at scale, how to get delisted, and why continuous monitoring beats one-time checks. - [AI email deliverability software — what it does and how to evaluate it](https://www.inboxplease.com/learn/ai-email-deliverability-software): AI improves open rates by improving inbox placement. What placement prediction, spam scoring, reputation trend analysis, and anomaly detection actually do — and what AI cannot fix. ## AI & Deliverability How AI outreach tools affect sender reputation, how ISP filters respond to AI-generated content, and what to check before scaling with tools like Clay and Instantly. - [Does AI-written cold email go to spam?](https://www.inboxplease.com/learn/does-ai-written-cold-email-go-to-spam): ISPs don't scan for AI authorship — but 51% of spam is now AI-generated, and filters are learning the patterns. The honest answer on risk, and what actually determines where your email lands. - [How ISPs detect AI-generated email](https://www.inboxplease.com/learn/how-isps-detect-ai-generated-email): No ISP runs a dedicated AI scanner on your content. Detection is indirect: reputation-based, engagement-based, and pattern-based. Here's how the two pathways work and what you can do about them. - [AI cold email and sender reputation](https://www.inboxplease.com/learn/ai-cold-email-sender-reputation): AI outreach tools reduce friction on volume. Volume with imprecise targeting produces the engagement signal degradation that moves domains toward spam. The mechanism, symptoms, and recovery path. - [Clay and Instantly deliverability guide](https://www.inboxplease.com/learn/clay-instantly-deliverability-guide): Clay and Instantly don't manage your sender reputation. Here's the checklist every team using these tools needs before scaling — authentication, warmup, placement testing, and domain strategy. ## Fixing problems Diagnosis and recovery guides for sender reputation damage, authentication failures, and spam folder placement. - [Why are my emails going to spam? Causes, diagnosis and fixes](https://www.inboxplease.com/learn/how-to-improve-email-deliverability): Six ordered steps: diagnose first with a placement test, fix authentication, check blacklists, clean your list, reduce complaint rates, and warm up if volume increased. Why the order matters and what not to do first. - [How to improve email sender reputation](https://www.inboxplease.com/learn/how-to-improve-email-sender-reputation): What sender reputation is, what damages it, how to check it across providers, and six proactive steps to improve it — whether building on a new domain, maintaining a healthy one, or recovering. - [How to fix your email sender reputation](https://www.inboxplease.com/learn/how-to-fix-email-sender-reputation): A six-step ordered guide: diagnose before you act, pause and clean your list, fix authentication, get off blacklists, rebuild with controlled volume, then monitor. What ISPs actually measure and why the order matters. ## By use case How deliverability challenges differ by team type, and what each use case needs to get right. - [Email inbox placement for sales teams](https://www.inboxplease.com/learn/email-inbox-placement-for-sales-teams): Sales teams face harder placement challenges than marketing: cold complaint risk, shared IPs across reps, continuous domain cycling, and a missed email means a missed meeting. What a placement service needs to do for sales specifically. ## Alternatives & comparisons How InboxPlease compares to the most-searched warm-up tools — honest about strengths, specific about gaps. - [Warmy alternative](https://www.inboxplease.com/alternatives/warmy): Warmy has the largest G2 review moat in the category. The two most common complaints: per-inbox pricing ($400–500/mo at 10+ inboxes) and silent disconnections (~42 G2 mentions). How InboxPlease compares across pricing, network transparency, and M365 support. - [Lemwarm alternative](https://www.inboxplease.com/alternatives/lemwarm): Free for Lemlist Email Pro+ subscribers. Concerns: almost no standalone review presence, disputed Smart Cluster matching, and a network reviewers describe as lacking transparency. The wedge is knowing exactly who is warming you. - [Folderly alternative](https://www.inboxplease.com/alternatives/folderly): Strong support (9.8/10 G2 score), Belkins-backed. Four concerns documented by reviewers: a 42,000-email weekend blowout from a bug, mandatory annual contracts, placement testing as a separate add-on, and inbox access required for audits. - [MailReach alternative](https://www.inboxplease.com/alternatives/mailreach): The best-supported tool in the category — 4.9 cross-platform, no G2/Trustpilot gap. The comparison is about scope: no free trial, no free placement test, 35-seed panel, no blacklist monitoring or DMARC analytics. - [Saleshandy alternative](https://www.inboxplease.com/alternatives/saleshandy): A mature cold email platform with sequences, inbox rotation, LinkedIn outreach, and bundled warm-up. If you only need deliverability, you're paying for an outreach stack you won't use — and getting a tool whose roadmap isn't built around your problem. - [Snov.io alternative](https://www.inboxplease.com/alternatives/snov): Prospecting and sales automation platform — email finder, data enrichment, drip sequences, and bundled warm-up. The comparison is about scope: if deliverability is the goal, Snov.io is a full sales stack that includes warm-up as one feature. - [Salesforge alternative](https://www.inboxplease.com/alternatives/salesforge): AI cold email platform built for multi-sender outreach at scale. Warmup is bundled via Primebox. The wedge: no blacklist monitoring, no DMARC analytics, no free placement test, and full inbox access required for outreach features. - [Warmforge alternative](https://www.inboxplease.com/alternatives/warmforge): AI-generated warmup conversations with a genuine free tier. A focused warmup tool — no inbox placement testing, no blacklist monitoring, no DMARC analytics, and full inbox access required vs. InboxPlease's send-only OAuth model. - [TrulyInbox alternative](https://www.inboxplease.com/alternatives/trulyinbox): Dedicated warmup and placement tool, not a bundled outreach feature. The comparison is about credential scope: TrulyInbox requires full inbox access for the engagement loop; InboxPlease uses send-only OAuth and never reads your inbox. - [Instantly alternative](https://www.inboxplease.com/alternatives/instantly): Multi-mailbox cold email platform with sequences, inbox rotation, A/B testing, and bundled warm-up via Warmly. If deliverability is the goal, you're paying for sequencing infrastructure you won't use — with no blacklist monitoring or free placement test. ## From the blog Editorial pieces on how the email deliverability category actually works. - [We never read your inbox](https://www.inboxplease.com/blog/we-never-read-your-inbox): Why most warm-up tools require full inbox access, how InboxPlease uses send-only OAuth instead, and the verbatim Terms of Service language under Google and Microsoft data-use commitments that makes this a structural constraint, not a marketing claim. - [Why every warm-up tool's G2 score is 4.8 and its Trustpilot score isn't](https://www.inboxplease.com/blog/g2-vs-trustpilot-warmup-scores): G2 captures users who reached proficiency. Trustpilot captures users who hit friction. The gap between them is a more predictive signal for the first 90 days than either score alone — and it exists for several major tools in this category. Not sure where to start? The free test checks your inbox placement, authentication, and blacklist status in 60 seconds — and tells you exactly what to fix. ## Test your deliverability now Inbox placement across Gmail, Outlook, and Yahoo. SPF, DKIM, and DMARC on a real delivered message. Blacklist status. 60 seconds, no account required.