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EMAIL BRIEFING

Email Deliverability: What It Is and How to Check It

Email deliverability is the share of messages accepted by recipients’ mail servers rather than returned with an error. It shows that an email reached the recipient’s mail system, but not that it landed in the inbox, was opened, or led to a reply. For Russia and the CIS, this distinction matters across corporate mail, Yandex 360 and Mail.ru inboxes alike.

Self-check
97.7%
of addresses accepted an email in our campaigns
3,224,000
emails sent

Why an accepted email does not yet create a reply opportunity

A recipient’s server may accept a message but place it in spam, a newsletters tab, or a shared inbox nobody reviews. Campaign reporting should therefore separate delivery failures from recipient response: the first concerns the technical route, while the second reflects the list, the reason for contact and the email itself.

SignalWhat it meansWhat to check
BounceThe server did not accept the emailThe address, recipient domain and server response
AcceptedThe email reached the recipient’s mail systemSender reputation and folder placement
ReplyThe recipient saw a reason to engageThe offer, recipient role and reply handling speed

In OT9’s own data, 97.7% of addresses accepted an email. That is not a promise of leads: 48,100 of 811,200 contacted companies replied, and 6,500 showed explicit interest in details, a proposal or a meeting. Read these metrics as a chain rather than treating one as a substitute for another.

What to find before the first send

A common problem is launching from a domain with only part of its sender authentication configured: SPF exists, but DKIM does not sign messages; or DMARC is published but does not align with the domain in the From field. The recipient sees the mismatch and has another reason to treat the message cautiously. Check all three records before launch: SPF, DKIM and DMARC.

  • Confirm that the sending domain receives inbound email and has a valid MX record.
  • Match SPF, DKIM and DMARC to the service actually sending the email, not merely to what appears in DNS.
  • Remove addresses with obvious format errors and duplicate contacts at the same company.
  • Separate catch-all addresses from verified addresses, because they need different verification logic.
  • Start with a controlled wave and investigate every delivery failure before expanding.

An info@ address is not automatically a bad contact, and a catch-all domain does not prove that a mailbox works. Decide from verification results and company context, not from one signal alone.

The issue often starts before infrastructure: with a purchased or outdated list. If a server says the mailbox does not exist, sending again will not repair the route. Verify and clean the list first, then look for another relevant contact at the same company through lead list building.

Campaign review: a bounce does not mean losing the account

Consider an industrial equipment supplier whose first email to a procurement contact bounces because the mailbox does not exist. The wrong response is to mark the company unreachable. A better response is to check the company website and public contacts, find a shared address or another person involved in procurement, then ask plainly who is reviewing a packaging-line replacement this quarter.

That question does not disguise an error as personalisation and gives the recipient a practical reason to forward the message. If messages bounce repeatedly from one recipient domain, pause that part of the campaign and diagnose it; if the cases are isolated, correct the company records.

  • Keep the technical reason returned by the server.
  • Check whether the error affects one mailbox or the whole domain.
  • Look for a new contact at the same company before widening the list.
  • Do not resend to the same nonexistent address.

When better delivery will not produce sales

Technical health does not solve the commercial problem when the offer is aimed at the wrong market or the email gives no concrete reason to talk. A company may accept every message, yet a commercial director will not reply to a vague promise to increase sales without knowing for whom, how, or why the question is relevant now.

Do not begin with domain configuration if you have no working ideal customer profile, company list or capacity to handle replies quickly. In that situation, validate the outreach scenario first through an outreach audit. Deliverability reduces technical loss; it does not create demand or qualification.

FAQ

Are email deliverability and inbox placement the same thing?

No. Deliverability records whether the recipient’s server accepted the email. Inbox placement concerns which folder receives it after acceptance, such as the inbox, spam or another category.

What bounce rate is a problem?

There is no single useful threshold without context. Review the reason for each bounce, the source of the addresses and whether the issue repeats across one recipient domain. A sudden increase is a reason to pause the wave and check both the list and sender setup.

Should you resend after a bounce?

Not to the same address when the server says the mailbox does not exist. Find another current contact at that company and send a new email that is relevant to their role. Repeating the same failed route does not improve delivery.

Do you need a separate domain for cold email?

It depends on your volume and existing infrastructure, but your primary company domain should not face uncontrolled sending activity. The preparation approach is covered in domain and mailbox warm-up.

Can deliverability be measured from replies alone?

No. No reply can reflect a technical problem, an outdated contact, a weak reason for reaching out or a busy recipient. You need bounce data, accepted-email data and a subsequent campaign review to understand what happened.

Check the route before you launch

We will review your list, domains and delivery-failure patterns within your setup. You will receive a prioritised list of fixes and a clear launch sequence.

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