Deliverability is the metric that makes every other email metric possible. A 50% open rate means nothing if only 60% of your emails reach the inbox. The other 40% landed in spam, bounced, or disappeared into the void.

Email deliverability depends on three things: your sender reputation, your authentication setup, and the infrastructure your email tool provides. You control the first two. Your email platform controls the third. Choosing a platform with strong deliverability infrastructure gives you a foundation to build on.

Here's which platforms consistently deliver emails to the inbox.

What Determines Email Deliverability

Sender reputation: Built over time based on engagement rates, complaint rates, bounce rates, and sending patterns. Good reputation means inbox placement. Bad reputation means spam folder.

Authentication: SPF, DKIM, and DMARC records that prove your emails are legitimately from you. Without these, email providers are suspicious.

Infrastructure: IP reputation, sending volume management, bounce handling, and feedback loop processing. This is what your email platform provides.

Content: Spam filters evaluate content for red flags (excessive caps, spam trigger words, misleading subject lines). But infrastructure and reputation matter more than content.

The 7 Best for Deliverability

1. Sequenzy

Best for: SaaS email deliverability with sender separation

Sequenzy provides deliverability infrastructure designed for SaaS email. The platform handles authentication setup (SPF, DKIM, DMARC guidance), manages sending reputation, and separates transactional and marketing sending. This separation prevents marketing email complaints from affecting transactional delivery.

For SaaS companies sending a mix of transactional email (receipts, notifications) and marketing email (campaigns, sequences), having built-in sender separation protects the emails that matter most.

Deliverability approach: Sender separation, authentication guidance, reputation management Best for: SaaS companies needing reliable delivery for transactional + marketing Pricing: From $29/month Pros: Sender separation built in, authentication setup, SaaS-focused Cons: Newer platform, smaller sending infrastructure than established providers

2. Postmark

Best for: The highest consistent deliverability in the industry

Postmark has built its entire brand around deliverability. The platform maintains strict sending policies, rejects spammers aggressively, and focuses exclusively on legitimate email. This keeps their IP reputation exceptionally clean.

Postmark publishes its delivery rates publicly (consistently 99%+ for transactional email). The platform separates transactional and marketing email into different "message streams" so marketing complaints never affect transactional delivery. Bounce handling is automatic and aggressive.

Deliverability approach: Strict sender policies, clean IP pools, separate message streams, public metrics Best for: Transactional email where every message must reach the inbox Pricing: From $15/month Pros: Best deliverability reputation, public metrics, strict quality, fast delivery Cons: Marketing features limited, strict policies may reject borderline senders

3. Amazon SES

Best for: High deliverability at scale with full control

Amazon SES provides the infrastructure for excellent deliverability, but requires you to manage it. You get dedicated IPs (at volume), authentication setup, and sending reputation management. SES also provides a Virtual Deliverability Manager that monitors and optimizes sending in real-time.

The deliverability advantage is control. You manage your own sending reputation, IP warming, and list hygiene. For teams with email operations expertise, this control produces better deliverability than shared infrastructure.

Deliverability approach: Customer-managed reputation, dedicated IPs available, sending optimization tools Best for: Teams with email expertise wanting maximum control Pricing: $0.10 per 1,000 emails Pros: Full control, dedicated IPs, Virtual Deliverability Manager, scalable Cons: Requires expertise, no hand-holding, you own the reputation management

4. Resend

Best for: Developer-friendly email with strong deliverability defaults

Resend focuses on transactional email with good deliverability baked into the defaults. The platform handles authentication setup, manages IP reputation, and monitors delivery metrics. For developers who want reliable delivery without becoming email experts, Resend provides a good foundation.

The delivery monitoring dashboard shows real-time delivery status, bounce rates, and complaint rates. Resend's relatively strict acceptable use policy helps maintain clean shared IP pools.

Deliverability approach: Managed IPs, authentication guidance, strict AUP, monitoring dashboard Best for: Developers wanting reliable delivery with minimal management Pricing: Free for 100 emails/day, from $20/month Pros: Good defaults, delivery monitoring, developer-friendly, clean IP pools Cons: Shared IPs (no dedicated option on lower tiers), newer platform

5. SendGrid

Best for: Deliverability tools and expertise at scale

SendGrid processes billions of emails and has extensive deliverability infrastructure. The platform offers dedicated IPs, IP warming tools, authentication management, and deliverability consulting (on higher plans). The Email Validation API helps prevent sending to invalid addresses.

SendGrid's expertise is in managing deliverability at scale. The platform provides tools for IP reputation management, suppression list management, and engagement-based sending. For high-volume senders, these tools prevent the deliverability problems that come with scale.

Deliverability approach: Dedicated IPs, IP warming, validation API, suppression management, expert consulting Best for: High-volume senders needing deliverability management tools Pricing: From $20/month, dedicated IPs on Pro plan Pros: Battle-tested at scale, dedicated IPs, validation API, expert support available Cons: Shared IP quality varies, deliverability tools on higher tiers, requires management

6. Mailgun

Best for: Deliverability infrastructure with email validation

Mailgun provides comprehensive deliverability tools: dedicated IPs, IP warming, email validation (check addresses before sending), and deliverability analytics. The platform's email validation API reduces bounces by catching invalid addresses before you send.

Mailgun's Inbox Placement feature tests where your emails land (inbox, spam, or missing) across major email providers. This proactive monitoring lets you catch deliverability problems before they affect your campaigns.

Deliverability approach: Dedicated IPs, email validation, inbox placement testing, analytics Best for: Teams wanting proactive deliverability management Pricing: From $15/month, validation API priced separately Pros: Email validation API, inbox placement testing, dedicated IPs, comprehensive tools Cons: Infrastructure-focused (no marketing features), requires setup

7. ActiveCampaign

Best for: Marketing email deliverability with engagement-based sending

ActiveCampaign maintains deliverability through engagement-based sending, list hygiene tools, and authentication management. The platform automatically handles bounces, processes complaints, and provides deliverability reporting.

ActiveCampaign's advantage for marketing email is the engagement-based approach. The platform helps you identify and suppress unengaged contacts, which directly improves sending reputation. For marketing campaigns where engagement rates drive deliverability, this proactive approach works well.

Deliverability approach: Engagement-based optimization, list hygiene, bounce handling, authentication Best for: Marketing email where engagement management drives deliverability Pricing: From $29/month Pros: Engagement-based deliverability, list hygiene tools, automatic bounce handling Cons: Shared IPs (dedicated on enterprise), less control than infrastructure platforms

Deliverability Best Practices (Regardless of Platform)

Authentication

Set up SPF, DKIM, and DMARC before sending any email. This is non-negotiable. Without authentication, your emails are more likely to be flagged as suspicious. Every platform provides guidance for this.

List Hygiene

Remove subscribers who consistently don't engage. Sending to unengaged contacts degrades your reputation. Remove hard bounces immediately. Consider removing contacts with no opens in 90-180 days.

Warm Up New Sending Infrastructure

Start with low volume and increase gradually when using a new domain, IP, or email platform. Sudden high-volume sending from an unknown sender triggers spam filters.

Monitor Complaint Rates

Keep spam complaint rates below 0.1%. Above 0.3% is a red flag that will damage your reputation. Major email providers (Gmail, Yahoo) will throttle or block senders with high complaint rates.

Consistent Sending Patterns

Send regular volumes on a consistent schedule. Large spikes in sending volume look suspicious to email providers. Gradual, predictable sending patterns build trust.

FAQ

What's a good inbox placement rate? For transactional email: 99%+. For marketing email: 95%+ is excellent, 90%+ is acceptable. Below 85% indicates infrastructure or reputation problems.

Does my email platform's deliverability matter more than my sending practices? Your sending practices matter more. The best infrastructure can't save a sender with a dirty list and high complaint rates. But good infrastructure provides a stronger foundation and better tools for maintaining deliverability.

Should I use a dedicated IP? At volumes above 50,000 emails/month with consistent sending patterns, a dedicated IP gives you full control over your reputation. Below that, shared IPs from reputable providers are usually fine.

How long does it take to build sender reputation? 4-8 weeks of consistent, engaged sending. Start with your most engaged subscribers and gradually increase volume. Attempting to send to your full list immediately on a new infrastructure is the fastest way to damage reputation.