3 Reasons Why Your Cold Email Isn't Reaching the COO

VPs of Sales and CMOs in B2B Tech companies send cold email campaigns to operations directors and observe a reply rate of 1.61 percent and a positive reply rate of only 0.27 percent – then, lacking data, they experiment with volume or copywriting, which generates further iterations without data and damages domain reputation with each unsuccessful campaign.

The average reply rate in cold email campaigns dropped to 5.8 percent in 2025 according to Belkins.io, and typical SDR outbound metrics are an open rate of 19-26 percent, a response rate of 1.5-4.89 percent, and a positive response rate of 0.4-0.6 percent according to AISDR from July 2024 – these ranges serve as a starting point for any diagnosis. Despite the low volume of responses, as many as 16.76 percent of responses from C-level executives are positive, while among directors, this percentage is only 5.2 percent according to Sales.co.

C-level executives in small tech companies react more positively than in enterprise, but only if the message actually reaches the right person – and not a junk folder or a label created by an assistant. The problem is not who you are targeting, but that you don't know at which stage you are losing the message.

Technical Block: Messages Don't Even Leave the Sender's Infrastructure

The first blocking mechanism appears before the message reaches the recipient's inbox. A bounce rate above 5 percent signals serious deliverability issues – a healthy rate, according to Mailgun, should remain below 2 percent, and any exceeding of this threshold means that messages are rejected by recipient servers or filtered by a Secure Email Gateway before any human sees them. When a campaign generates such a level of bounces, messages land in Secure Email Gateway filters or are rejected at the SPF, DKIM, and DMARC configuration stage – the VP of Sales receives no signals that the problem lies in domain reputation or the use of suspicious TLDs.

Delivery rate measures whether the email reached the recipient's server, whereas inbox placement rate measures only emails that landed in the primary folder – a message can have a 100 percent delivery rate and simultaneously a 0 percent inbox placement rate, because the SEG automatically moves it to spam before the recipient sees it. The SEG scans headers, content, links, and attachments – each of these elements can trigger a filter regardless of correct SPF, DKIM, and DMARC configuration. A spam complaint rate above 0.3 percent constitutes a third diagnostic indicator alongside bounce rate – exceeding it signals that messages are reaching inboxes, but recipients are actively marking them as spam, which destroys domain reputation faster than a high bounce rate.

The average open rate in B2B campaigns is 42.35 percent according to HubSpot, but with a concurrent bounce rate exceeding 5 percent, this indicator drops dramatically because messages never achieve a good inbox placement rate. In such a situation, any changes in email length – even the optimal 6-8 sentences under 200 words, which yield a 6.9 percent reply rate according to Belkins.io – remain meaningless, because the content does not leave the sender's server. A cold email to an operations director does not reach the decision-maker when the corporate cold email spam filter operates at the infrastructure level.

Diagnostic signals of a technical block include: - Bounce rate above 5 percent with an open rate below 20 percent. - Spam complaint rate above 0.3 percent. - Inbox placement rate significantly lower than delivery rate. - Use of suspicious TLDs or lack of proper SPF, DKIM, DMARC configuration.

How to distinguish from other blocks: when the bounce rate exceeds 5 percent and the open rate falls below the 19-26 percent benchmark for cold outbound, the problem lies in the infrastructure, not the gatekeeper or the value proposition.

Organizational Block: Messages Arrive, but Not to the COO

The second mechanism operates on the recipient's organization side. Assistants, operational teams, and automatic rules in Outlook or Gmail filter communication before the operations director sees it – responses like "please contact department X" or automatic messages from info@ addresses indicate that the message has been intercepted at the gatekeeper level. An assistant blocks a cold email when an Outlook rule automatically redirects emails to a collective inbox or a "to review" folder.

The open rate may hover around 19-26 percent, but the reply rate from C-level executives drops to zero, while responses appear from lower levels of the organization. C-level executives in companies with 1-50 employees in the software, internet, IT services, fintech, and biotech industries react more positively – in large enterprises, effectiveness decreases, and it's better to target people closer to the operational pain, not necessarily VPs or C-level. A cold email does not reach the decision-maker when an assistant blocks the cold email at the human or automatic filter level.

Diagnostic signals of an organizational block include: - Responses from info@, contact@, or noreply@ addresses with no response from the COO's address. - Responses from assistants or operational coordinators asking to contact another department. - Open rate of 19-26 percent with a near-zero reply rate from C-level, while responses appear from lower levels. - Quick email opens within minutes of sending with no response.

How to distinguish from other blocks: when the open rate is within the 19-26 percent range, and responses come only from lower levels with simultaneous silence from C-level, the problem lies with the gatekeeper, not the infrastructure or content.

Behavioral Block: The Message Is Opened, but Generates No Response

The third mechanism appears when the message lands in the COO's primary inbox and is opened. The C-level reply rate is 1.61 percent, and the positive reply rate is only 0.27 percent – assuming correct deliverability, this indicates a problem with value proposition alignment, personalization, or CTA. Adding a third email in a sequence reduces the reply rate by about 20 percent, whereas one-touch sequences can achieve better results than longer strings.

Emails of 6-8 sentences under 200 words achieve an open rate of approximately 42.67 percent and a reply rate of 6.9 percent according to Belkins.io – this is the best result in the study. Emails longer than 13+ sentences (600+ words) show a clear drop in both open rate and reply rate. When the open rate is in the 30-45 percent range, and the reply rate falls below 0.2-0.3 percent with a bounce rate below 2 percent and no spam complaints, the dominant cause is precisely a behavioral block, not a technical or organizational one. Optimizing a cold email from scratch begins with shortening the message to 6-8 sentences.

Diagnostic signals of a behavioral block include: - Open rate in the 30-45 percent range with a reply rate below 0.2-0.3 percent. - Bounce rate below 2 percent and no spam complaints. - Sequences longer than one-touch with a 20 percent lower reply rate.

How to distinguish from other blocks: when the open rate is in a solid 30-45 percent range, and the reply rate remains below 0.2-0.3 percent with proper deliverability, the problem lies in the message, not the infrastructure or the gatekeeper.

Diagnosis Before Content Correction

Understanding which of the three mechanisms is blocking the campaign allows VPs of Sales and CMOs to start corrections from the right place. Secondary domains are domains similar to the corporate one – for example, company-outreach.com instead of company.com – which build their own sender reputation independently of the main domain. If a test campaign destroys the reputation of a secondary domain, the corporate domain remains untouched. External IP clusters eliminate the risk that outbound activity will affect the deliverability of internal company mail – this architecture does not require access to client mail servers or IT department involvement.

B2B cold email is legal based on legitimate interest, provided a LIA analysis is conducted and the scope of processed data is minimized – the name, surname, and business email address of the COO fall within this scope. External outbound infrastructure (secondary domains, IP clusters) does not process data on client servers, which eliminates the risk of GDPR violations on the client's side. The corporate cold email spam filter and assistant blocking cold emails become less threatening when the campaign is based on isolated infrastructure.

The diagnostic framework is as follows: - A bounce rate above 5 percent plus a low open rate means a technical block – start by auditing SPF, DKIM, DMARC, and domain reputation. - An open rate of 19-26 percent plus responses from lower levels and no C-level responses means an organizational block – change your targeting strategy or addressing method. - An open rate of 30-45 percent plus a reply rate below 0.2-0.3 percent with a bounce rate below 2 percent means a behavioral block – start by shortening the email to 6-8 sentences and simplifying the CTA.

The three blocking mechanisms rarely work in isolation – in most campaigns, one dominates, but the other two reinforce it, meaning correcting one element without diagnosing the others yields only partial results. If you are observing a campaign to COOs in SMB tech companies – what metrics are you seeing, and which blocking mechanism do you diagnose as dominant?