Overview

Sending.ac provides cold email infrastructure built on Azure that lets users send thousands of emails daily from just a few domains. It automates DNS setup (SPF, DKIM, DMARC) with 34-second mailbox provisioning, offers 100% domain isolation with dedicated Azure tenants and IPs per domain, and includes IP rotation every 14 days. The platform eliminates the need for hundreds of domains by enabling up to 75 inboxes on a single domain, reducing domain costs significantly. Inboxes self-import into outreach tools like Instantly and Smartlead within hours. Features include self-diagnosing deliverability with seven daily checks per domain, free mailbox insurance, and native integration with sequencers. The infrastructure is pre-warmed and self-diagnosing, with automated alerts for issues like DMARC failures or registrar resets. Users can build custom plans mixing providers via a configurator, and warm-up pool checks work on any infrastructure for free.

Key Features

High-Volume Single Domain Sending

Send thousands of emails per day from just a few domains; a single domain outperforms 25+ domains from GSuite or Outlook, with up to 75 inboxes on one domain.

Unlimited Mailbox Creation

Generates unlimited mailboxes under one domain to support sequencing and scaling of outreach campaigns.

Automated DNS Setup

Automatically configures SPF, DKIM, and DMARC records, provisioning inboxes in about 34 seconds per mailbox.

Accelerated Warm-Up Engine

Reduces domain warm-up time from weeks to days, enabling rapid campaign launches.

100% Domain Isolation on Azure

Every domain gets its own Azure outbound tenant with unique IPs, DKIM, WhoIs, and IMAP; no shared IPs or cross-contamination; IPs auto-replaced every 14 days.

Outreach Tool Integration

Inboxes self-import into outreach tools (Instantly, Smartlead, etc.) within hours after ordering, fully automated.

Simplified Management

Eliminates complex infrastructure planning and monitoring, streamlining outreach operations.

Self-Diagnosing Deliverability

Seven deliverability checks on every domain, every day, with automated alerts when issues are detected (e.g., DMARC failures, registrar resets).

Free Mailbox Insurance

Infrastructure replacement and automatic reconnects included at no extra cost.

Native Sequencer Integration

Zero-distance integration with sequencers; warm-up pool checks and clones work on any infrastructure for free.

Pre-warmed Mailboxes

Mailboxes arrive warm on whatever domain extension you want to send from, eliminating manual warm-up delays.

Verified Warm-up

Warm-up you can finally verify with transparent checks, ensuring deliverability before scaling.

Build-your-own Plan Configurator

Flexible pricing plans allowing you to mix providers and build custom plans per domain and per mailbox.

Cross-infrastructure Warm-up Pool Checks

Warm-up pool checks and clones work on any infrastructure for free, not just sending.ac mailboxes.

Pros & Strengths

✓

Simplified Management: Consolidates outreach operations, reducing the need for multiple domains and mailboxes.

✓

Time Efficiency: Automated inbox provisioning (34 seconds) and fast warm-up cut setup time dramatically versus manual processes.

✓

Scalability: Enables rapid expansion of email volume without the logistical burden of managing many domains; up to 75 inboxes per domain.

✓

Cost Savings: Replaces 100+ domains costing $1,500+ with a few domains at $50; $0.50 per inbox pricing includes enterprise-grade Azure IPs.

✓

Superior Isolation: 100% domain isolation with dedicated Azure tenants and IPs eliminates shared risk; IP rotation every 14 days maintains deliverability.

✓

Proactive Deliverability Monitoring: Self-diagnosing infrastructure with seven daily checks per domain alerts you to issues before clients notice.

✓

Free Infrastructure Insurance: Automatic reconnects and infrastructure replacement included at no additional cost.

✓

Pre-warmed Mailboxes: Mailboxes arrive warm on any domain extension, eliminating manual warm-up delays.

✓

Verified Warm-up: Transparent warm-up verification ensures deliverability before scaling campaigns.

✓

Flexible Plan Configurator: Build custom plans mixing providers per domain and per mailbox for optimal cost and deliverability.

✓

Cross-infrastructure Compatibility: Warm-up pool checks and clones work on any infrastructure for free, not just sending.ac mailboxes.

Cons & Tradeoffs

⚠

Limited Public Information: Scarcity of detailed feature descriptions and user reviews makes it difficult for prospects to evaluate suitability.

⚠

Azure-Specific Infrastructure: Platform is built exclusively on Azure, which may not align with organizations requiring multi-cloud or on-premise solutions.

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Lower Inbox Density: Maximum of 75 inboxes per domain compared to previously claimed 150, requiring more domains for very high volume.

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Self-diagnosing Dependency: Reliance on automated self-diagnosing system may not catch all edge cases without human oversight.

Known Limitations

• Sparse public documentation and reviews hinder assessment of product capabilities.

• Platform is Azure-exclusive, limiting infrastructure flexibility.

• Maximum 75 inboxes per domain may require additional domains for very high-volume campaigns.

• Self-diagnosing system may not replace human expertise for complex deliverability issues.

Pricing & Plans

Model: subscription

USD0.5 /month

Flexible pricing per domain and per mailbox with configurable plans; $0.50 per inbox per month on Azure infrastructure with automated DNS setup and 100% domain isolation. Build-your-own-plan configurator allows mixing providers. Pricing is per domain and per mailbox with fixed plans available.

✓ Free Plan ✓ Free Trial

Pricing verified: 2026-08-20

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