TL;DR

Outreach platforms like Sourcewhale and TrackerRMS can verify that your technical authentication is set up correctly, but they can’t control or diagnose everything that affects inbox placement.

Deliverability problems often sit at the level of IP reputation, sending behaviour patterns, and domain history. None of which a CRM provider manages on your behalf.

These issues tend to build gradually and then feel sudden, which is why recruiters are often blindsided.

A proper deliverability audit looks at layers the platform simply doesn’t have visibility of. That’s where Quinset comes in.

If you’re running cold outreach through a platform like Sourcewhale, TrackerRMS, or Bullhorn Automation, and your inbox placement has started to slide, there’s a decent chance you’ve already been through the same loop.

You contact support. They check your SPF record. They confirm your DKIM is passing. They tell you your authentication looks fine from their end. And technically, they’re right.

That’s not them brushing you off. It’s a genuine answer. They’ve checked that their SPF and DKIM records are present on your domain, but they aren’t checking for any other tools or services you use. Your ATS, your marketing platform, your job board integrations: all of these may also be sending email on behalf of your domain, and the platform has no visibility of any of them. The other problem is that authentication being correct is necessary but not sufficient for reliable inbox placement. There’s a layer underneath all of that (one the platform can’t see and wouldn’t be expected to fix) where the real problem usually lives.

This article explains what that layer is, why it causes problems for recruitment agencies specifically, and what a proper diagnosis actually involves.

What Your Outreach Platform Can (and Can’t) Control

Platforms like Sourcewhale, TrackerRMS, and similar tools do a genuinely good job of the things within their scope. They help you build campaigns, manage sending windows, track opens and replies, and critically they walk you through setting up SPF and DKIM so your emails are authenticated correctly.

Authentication tells receiving mail servers that you are who you say you are. It’s foundational. Without it, you’re in serious trouble. But authentication is a pass/fail check. It doesn’t tell Gmail or Microsoft Outlook whether your emails are wanted. And that’s a very different question.

What outreach platforms can control:

Whether your authentication records are in place
The timing and spacing of your campaigns
The technical format of your emails (headers, encoding, unsubscribe links)
Sending limits, where the platform enforces them

What they can’t control:

The reputation of the IP address your emails are sent from
How receiving servers have come to regard your domain over time
Whether your sending patterns look like bulk commercial email to a spam filter
What happens when Microsoft decides your sending behaviour crosses a threshold

That last category is where most of the problems actually live.

The IP Reputation Problem Nobody Mentions

When you send email through an outreach platform, your messages leave via that platform’s sending infrastructure, which in most cases means shared IP addresses.

A shared IP pool is exactly what it sounds like: your emails, and the emails of thousands of other users on the same platform, all go out through the same small set of IP addresses. The reputation of those IPs is built collectively. If other users on the same pool are sending at high volume, hitting spam traps, or getting flagged, the IP reputation takes a hit and your emails are affected.

This isn’t a design flaw or a reason to distrust the platform. It’s just the reality of how email infrastructure works at scale. Most platforms manage shared pools reasonably well. But “reasonably well” still means your deliverability is partially a function of what your neighbours are doing.

Some platforms offer dedicated IPs, but they come with their own requirements, primarily that you need to send enough volume to warm and maintain them. A dedicated IP with low volume can actually perform worse than a healthy shared pool.

The deeper issue is that IP reputation is only one variable. And increasingly, it’s not even the most important one.

Domain Reputation Is What Mailbox Providers Are Really Watching

Google and Microsoft have both shifted their filtering systems towards domain-level reputation signals over the past few years. What this means in practice is that the history of your domain (not just the IP it was sent from) is a significant factor in whether your emails reach the inbox.

Domain reputation is built up (and damaged) over time based on a range of signals:

How many of your emails get marked as spam by recipients
How often people engage positively (opens, replies, clicks) versus ignoring or deleting
Your historic bounce rates and whether you’re hitting invalid addresses
Whether your domain has appeared on blocklists
How consistently you authenticate and how long you’ve been doing it

Your outreach platform has no visibility of most of these signals. They can see whether authentication passed. They can’t see your domain’s standing in Google’s Postmaster Tools, whether your Microsoft sender reputation score has degraded, or whether you’ve accumulated spam complaints that have started to compound.

And because recruitment agencies are often running large candidate databases with email addresses collected over years, the data quality problems that drive poor domain reputation are extremely common. An ATS built up over five or ten years will typically contain a meaningful percentage of addresses that are now defunct, role-based, or simply unengaged, and every campaign sent to those contacts is chipping away at your domain’s standing with the mailbox providers.

How Sending Behaviour Triggers Filters Even With Clean Authentication

There’s a category of spam filter logic that has nothing to do with whether your SPF record is valid. It’s behavioural. Modern filtering systems are trained to recognise patterns that look like bulk commercial email, and they’re quite good at it.

Some of the patterns that get recruiters into trouble:

Sending velocity. A domain that goes from sending 20 emails a day to 500 overnight is going to get scrutinised, even if those 500 emails are to legitimate contacts. Outreach tools make it easy to fire up a large campaign quickly, and that velocity spike can trigger rate limiting or filtering at the receiving end.

Low engagement rates. If a high proportion of your outreach emails are being opened and then immediately deleted, or simply never opened at all, mailbox providers interpret that as a signal that recipients don’t want the mail. Over time, those signals accumulate. Your campaign might be perfectly compliant technically, but if your contact list hasn’t been cleaned in two years, the engagement data will be telling a different story.

Content patterns. Certain phrases, link structures, and formatting choices correlate with spam in the training data that filters are built on. A recruiter using template-heavy campaigns with aggressive subject line formatting can inadvertently produce emails that pattern-match to commercial spam, even if the content is entirely genuine.

Reply-to or tracking domain mismatches. Outreach platforms often use tracking subdomains to monitor opens and clicks. If those subdomains aren’t correctly configured, or if they’re on a different domain to your sending address without proper alignment, that inconsistency can weigh against you.

None of these are things the platform can fix on your behalf. They’re either in your infrastructure, your contact data, or your sending practices, all of which sit outside the tool’s scope.

Why the Problem Feels Sudden (When It Isn’t)

One of the most common things I hear from recruiters who reach out to Quinset is some version of: “Everything was fine, and then overnight it just stopped working.”

It’s almost never overnight. What tends to happen is that a problem builds gradually over weeks or months: poor data quality, a mild IP reputation issue, engagement rates slowly declining, until the mailbox provider’s filtering model tips a threshold, and then the change in inbox placement is dramatic and immediate. The deterioration is gradual; the consequence is sudden.

This makes it genuinely confusing to diagnose without looking at the right data. The outreach platform has no reason to flag the gradual decline because everything within its scope was working correctly. By the time the recruiter notices a problem, there’s often several compounding factors at play simultaneously.

This is also why “just switch platforms” is rarely the answer. The domain reputation issue, the contact list quality problem, and the sending behaviour patterns come with you to the new tool.

What a Deliverability Audit Actually Looks At

A proper deliverability audit goes several layers deeper than a platform health check. At Quinset, here’s what we examine:

Domain health. Your SPF, DKIM, and DMARC records, including whether they’re actually aligned correctly, not just present. A DMARC policy sitting at p=none is not protecting you or giving you usable data. We also look at your domain age, MX records, and any associated subdomains being used for sending or tracking.

Sender reputation data. This means actually pulling your domain’s status from Google Postmaster Tools (which most agencies have never set up), checking your Microsoft SNDS data, and running your domain and any sending IPs against the major blocklist databases. These aren’t checks a platform runs, but they tell you a great deal about why mail is or isn’t landing.

Contact list quality. We look at bounce patterns, spam complaint rates where visible, and the composition of your sending list. A list with a high proportion of role-based addresses (info@, recruitment@, hr@) or addresses that haven’t engaged in two or more years is a direct contributor to poor reputation signals.

Sending behaviour and infrastructure. How is your outreach tool configured? What subdomains are you using for tracking? Are your reply-to addresses aligned with your from address? Is your sending volume appropriate for your domain’s warmup history? Are you on a shared or dedicated IP, and is that the right setup for your volume?

Content and template review. We look at the emails themselves, not to rewrite them, but to identify structural or content patterns that are likely to trigger filters.

DMARC reporting. If you’re on Quinset Powermail, we can pull your DMARC aggregate data to see exactly which sources are sending on your behalf and whether any are failing authentication. This is often where hidden third-party sending (from job boards, ATS notifications, or marketing platforms) turns up unexpectedly.

That’s a very different scope to what a platform support team can or should be doing. They’re there to help you use the tool correctly. We’re there to help you understand what’s happening to your email after it leaves the tool.

What This Means for Recruiters

If you’re running cold outreach campaigns and your inbox placement isn’t what it should be, the most useful thing to know is that the problem is almost certainly diagnosable. It just requires looking in the right places.

Switching platforms won’t fix a domain reputation issue. Tweaking your subject lines won’t fix a spam trap hit. Adjusting your sending window won’t fix a DMARC policy that’s not giving you any data.

The outreach tools that refer clients to Quinset do so because they understand the distinction. Their job is to run your campaigns efficiently. Our job is to make sure the infrastructure those campaigns run on is actually capable of delivering to the inbox.

If your platform has told you everything looks fine technically, that’s worth taking at face value. It probably does. The work is in the layer underneath.

Frequently Asked Questions

My outreach platform has a deliverability score. Doesn’t that tell me if there’s a problem?

Platform-side deliverability scores are useful but limited. They typically reflect whether your authentication is in place, whether your sending volume is within platform limits, and sometimes whether your domain appears on a major blocklist. They don’t reflect your standing with individual mailbox providers, your domain reputation history, your contact list quality, or behavioural signals that have accumulated over time. A green score means the platform’s checks passed. It doesn’t mean your emails are reaching the inbox.

We’ve been using the same tool and domain for years with no problems. Why is this happening now?

A few things tend to converge for agencies who’ve been running the same setup for a long time. Contact databases accumulate stale data. Sending volumes increase as teams grow and campaigns expand. Mailbox providers tighten their filtering. Microsoft in particular has made several significant changes over the past 18 months. What worked in 2021 on a list that was fresh then may be actively causing problems on the same list in 2026. The infrastructure hasn’t changed, but the environment it operates in has.

Can’t I just move to a dedicated IP to fix this?

A dedicated IP solves the shared-pool problem, but it introduces a new one: you have to warm it up correctly, and you need sufficient sending volume to maintain a positive reputation on it. If you switch to a dedicated IP and continue sending to a stale contact list with low engagement rates, the dedicated IP will develop its own poor reputation quickly. Dedicated IPs are the right answer in the right circumstances. They’re not a universal fix.

Is this something we can sort out ourselves, or do we need a specialist?

Some elements are straightforward to check yourself. There are free tools that will test your SPF and DKIM, and Google Postmaster Tools is free to set up. But interpreting what you find, prioritising which problems to address first, and knowing what a “normal” benchmark looks like for a recruitment agency’s sending patterns is where specialist knowledge becomes useful. Most agencies that contact Quinset have already tried to fix things themselves and have hit the limits of what a self-serve approach can do.

How long does a deliverability audit take, and what does it involve?

Our audits are thorough but efficient. We typically work through the full scope (domain health, sender reputation data, infrastructure, list quality, and DMARC reporting) and come back with a prioritised set of findings and recommendations. The timeline depends on the complexity of your setup, but most agencies have a clear picture within a week of starting. You can book a free initial consultation here to talk through what you’re seeing before committing to anything.

Nedd expert help?

If your outreach tool is working correctly and your emails still aren’t landing, the problem isn’t the platform. Book a free consultation and we’ll tell you exactly where to look.