Which delivery failures should you separate in reporting?
A hard bounce indicates a persistent issue: the mailbox was removed, the domain does not exist, or the address contains an error. Remove that contact from the current sequence. A soft bounce points to a temporary reason, such as a full inbox or an unavailable server, so read the server response before treating the address as invalid.
| Signal in the response | What it means | Action |
|---|---|---|
| Recipient does not exist | Hard bounce | Exclude the address and find another company contact |
| Mailbox is full | Soft bounce | Retry later without attachments |
| Server is temporarily unavailable | Soft bounce | Review a later resend |
The error code is more useful than a generic “not delivered” status. A nonexistent recipient is a contact-data issue; temporary unavailability is a sending-time issue. Before launch, use email list verification rather than guessing from a single message.
Why do bounces reduce more than campaign reach?
Every failed delivery reduces the number of companies that can actually see your offer. Repeatedly sending to known-dead addresses also creates a negative signal for your sending infrastructure, so bounces must be measured separately from interest in the offer: a relevant message may simply never reach the decision-maker.
Across our campaigns, 97.7% of addresses accepted an email and the bounce rate was 2.3%. This describes the address data in those campaigns, not the quality of a particular offer. No list stays perfect: companies change domains, employees leave, and old addresses disappear.
A failed address does not mean a lost company. If the account and target segment remain relevant, find another corporate address or another decision-maker to contact.
Where does the route to the recipient usually break?
A common mistake is taking an email from an old directory and treating any bounce as “the company does not respond.” For example, a message to a named employee may return because that person has left. A relevant general purchasing address can still lead you to the person responsible, especially when the opening question is specific to the company’s work.
How to review a bounce
Replacing the address and forwarding the same thread is usually a poor tactic. The new recipient has not seen the earlier emails, so a follow-up has no context. Start a standalone first message; see cold email for the principles behind it.
When will bounce reduction not solve the problem?
Cleaning addresses will not fix a campaign without a clear ideal customer profile or a list built too broadly without checking role and reason to engage. It also will not help when messages are delivered but every recipient receives the same generic proposal. In those cases, the problem is recipient selection and the first message, not bounces.
Do not pursue the lowest possible bounce rate by automatically excluding general inboxes such as info@ or sales@. Some are actively monitored, particularly in Russia and the CIS, where decision-makers often read their own business email. Judge them using the specific list and the server response, alongside email deliverability.
- Maintain a separate hard-bounce list rather than one catch-all “errors” folder.
- Have a process for finding a second address at valuable target companies.
- Do not mechanically copy a sequence when retrying after a soft bounce.
- Keep bounces separate from replies and qualified leads in reporting.