Deliverability Monitoring: Placement Tests & Health Checks

Most outbound teams think they're monitoring deliverability by watching their bounce rate. They see a <1% bounce rate and assume everything is fine, even as reply rates mysteriously drop. This was a passable strategy in 2018.

In 2025, it's a recipe for failure. Relying on bounce rates is like checking for a fire by waiting for the building to collapse. Google and Microsoft won't send you a notification that your domain is being throttled or sent to spam; they just do it silently. By the time your bounce rate spikes, your reputation is already damaged.

Serious outbound operations now treat deliverability as an active, continuous monitoring problem, not a passive dashboard metric. This requires an infrastructure-first approach that combines automated placement testing (to see where you're landing) with constant health checks (SPF, DKIM, blocklists) across your entire domain and inbox pool.

The standard approach to deliverability has been dangerously simple: set up an inbox, launch a campaign, and keep an eye on the bounce rate inside your sending tool.

If bounces stay low, you assume everything is working. If reply rates drop, the blame falls on the copy, the offer, or the lead list. The underlying delivery mechanism is treated as a black box that is assumed to be functional.

This breaks because the most common deliverability failures are silent. Your emails aren't bouncing; they're just being routed directly to the spam folder. Your dashboard looks green, but your pipeline is drying up because no one is seeing your messages. You're flying blind, making decisions based on lagging indicators that only signal a problem long after the damage is done.

An infrastructure-first approach treats deliverability as a system to be actively monitored and managed. It's not about watching a single metric; it's about having visibility into the entire sending stack.

1. Automated Placement Testing: This is the core of modern monitoring. It involves sending your campaigns to a seed list of inboxes across all major providers (Google Workspace, Outlook 365, etc.). This doesn't just tell you if it was delivered, but where it was delivered: inbox, promotions, or spam. It's the only way to get a real-time, accurate picture of your inboxing rate.
2. Continuous Health Checks: Your infrastructure's health is dynamic. You need automated systems to constantly check for correct SPF, DKIM, and DMARC configurations across all sending domains. This also includes automated monitoring of major blocklists to catch issues the moment they appear.
3. Warmup as a Diagnostic: A healthy, continuous warmup process is a leading indicator of deliverability health. When you see warmup emails starting to land in spam, it's the earliest possible warning that a domain's reputation is degrading, allowing you to pull it from live campaigns before performance suffers.
4. Data-Driven Rotation: Monitoring data isn't just for reports; it's for action. When placement tests show a domain's inboxing rate is dropping, an automated system should rotate it out of active sequences and into a recovery/warmup cycle, replacing it with a healthy, warmed-up domain from the pool.

Implementing a robust monitoring strategy doesn't happen overnight. It's a phased process of gaining visibility, stabilizing your assets, and then automating management.

Phase 1: Establish a Baseline. Before changing anything, get visibility. Implement placement testing and automated health checks on your current sending infrastructure. This gives you a clear, honest assessment of where you stand right now. You can't fix what you can't see.

Phase 2: Remediate and Stabilize. Use the data from Phase 1 to fix what's broken. This might mean delisting domains from blocklists, correcting DNS records, or retiring burned-out inboxes. The goal is to get your entire sending pool to a known, healthy state.

Phase 3: Automate Rotation and Recovery. With a healthy infrastructure, you can build the logic for proactive management. Set up rules to automatically pause sending from domains whose placement scores drop below a certain threshold. This shifts you from being a firefighter to being an architect.

Phase 4: Integrate and Optimize. Connect your deliverability data with your campaign performance data. Correlate a drop in reply rate for a specific sequence with the deliverability scores of the domains that were used to send it. This closes the loop and allows you to make smarter decisions about both your infrastructure and your campaigns.

Your CRM is built for managing customer relationships, not the physics of email deliverability. Simple email plugins are just mail-merge tools; they have no concept of domain reputation, placement testing, or automated health monitoring.

Trying to bolt a monitoring strategy onto these tools is inefficient and brittle. You end up with a mess of disconnected spreadsheets and third-party tools that don't talk to your sending platform, preventing any real-time, automated action.

SuperSend is built as the dedicated outbound execution and infra layer that sits alongside your CRM and data tools. It integrates placement testing, automated health checks, and domain rotation into a single system. Instead of just sending emails, it manages the health of the entire infrastructure required to ensure those emails actually land in the inbox at scale.

Once your monitoring infrastructure is sound, the next step is to explore the multi-channel sequence patterns this enables. You can find proven templates in our sequence library.