sendrules
Product
  • Overview
    How sendrules fits between your app and every provider.
  • SMTP Proxy
    One endpoint. Every provider you already trust.
  • Grid & Rules
    Six routing strategies. Coverage warnings. Failover.
  • Quality Gate
    Verify recipients before the send, not after the bounce.
  • ISP Routing
    Route by the recipient's live MX record — not domain strings.
  • Ramp-up
    Auto-advancing cap with bounce/complaint safety gates.
  • Limits & Queue
    Four-tier caps. Queue, don't drop. Midnight-UTC release.
  • Webhooks
    HMAC-signed. Retried on schedule. Replayable.
  • Activity
    Seven filtered inboxes. Sparklines. Share links.
  • Inbound
    Receive + classify replies, bounces, and OOOs.
  • Autoresponder Parser
    Harvest contacts from OOO replies into lists — webhook or CSV.
Deliverability
  • Overview
    The suite most vendors sell separately.
  • DMARC Monitoring
    rua ingest with per-source breakdowns.
  • Auth Check
    SPF / DKIM / DMARC, graded A through F.
  • Postmaster Tools
    Google Postmaster data in per-domain views.
  • Blocklists
    Continuous blocklist + seed-list inbox placement.
How it Works
Industries
  • All industries
    Every segment sendrules fits — and why.
  • B2B SaaS
    Transactional at scale. Failover across ESPs.
  • E-commerce & Retail
    One rule per ISP — Gmail buyers routed differently to Yahoo.
  • Marketing Agencies
    Per-client rules on your clients' own provider accounts.
  • Sales Development
    Verify every address. Parse every autoresponder for referrals.
  • Recruitment & Staffing
    OOO replies are full of decision-maker names — capture them.
  • Real Estate & Lead Gen
    Inquiry email hygiene + reply-source enrichment.
  • Financial Services
    DMARC compliance, audit log, signed webhooks.
  • Healthcare & Life Sciences
    Reliable patient comms with a full audit trail.
  • EdTech & Education
    Enrollment-week bursts absorbed by queue-don't-drop.
  • Nonprofit & Fundraising
    Donor-appeal deliverability without a deliverability team.
  • Publishers & Media
    Newsletter deliverability + list hygiene at every send.
  • Government & Public Sector
    IP allow-list at AUTH, DMARC-first, tenant isolation.
PricingDocs
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SMTP relay adapter

Mailcrux + sendrules — one endpoint, your account.

Mailcrux SMTP relay.

Attach MailcruxSee all integrations
What you keep

Your Mailcrux account, unchanged.

You keep your Mailcrux SMTP credentials and per-domain setup. sendrules relays as-is.

What sendrules adds

Routing, verification, and observability on top.

  • Grid & Rules routing — attach Mailcrux to a Grid alongside other providers and route by strategy or MX.
  • Inline Quality Gate — six per-recipient checks before Mailcrux ever sees the address.
  • 4-tier limits + queue-don’t-drop — cap by rule, provider, pair, or mailbox.
  • Ramp-up + safety holds — auto-warmup with bounce and complaint gates.
  • Observability — per-message route log with the exact reason for every decision.
How to attach

Attach Mailcrux in under two minutes.

The Add Provider wizard prompts for host, port, TLS mode, and username — with sensible defaults pre-filled for Mailcrux. A pre-flight Test Connection button validates the credentials against Mailcrux before you save.

Also supported

Every other provider you already use.

sendrules is BYO-provider — attach as many as you want in one tenant.

Custom SMTP

Any SMTP relay you already have credentials for.

Setup guide

Google Workspace

SMTP relay through a Workspace account.

Setup guide

AWS SES

Amazon SES via the SESv2 native API.

Setup guide

SendGrid

SendGrid via SMTP with an API key.

Setup guide

Mailgun

Mailgun via the messages.mime API.

Setup guide

Postmark

Postmark via SMTP with a server token.

Setup guide

Attach Mailcrux to your first Grid.

Start freeSee all integrations
sendrules

One SMTP endpoint across 15 providers. Verify recipients before the send, route by real MX, and monitor DMARC in the same product.

Sign inStart free

Product

  • SMTP Proxy
  • Grid & Rules
  • Quality Gate
  • ISP Routing
  • Ramp-up
  • Limits & Queue
  • Webhooks
  • Activity
  • Inbound
  • Autoresponder Parser
  • Integrations
  • Changelog

Deliverability

  • DMARC Monitoring
  • Auth Check
  • Postmaster Tools
  • Blocklists
  • Free Tools
  • Providers

Solutions

  • How it Works
  • Industries
  • Customers
  • Pricing
  • Docs
  • Contact

Company

  • About
  • Security
  • Status
  • Terms
  • Privacy
  • DPA
  • Acceptable Use

sendrules.com — marketing. Sending infrastructure operates separately at smtp.sendrules.net. © 2026 sendrules.com

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