Hard bounces vs soft bounces
A hard bounce is a permanent failure: the mailbox or domain does not exist. A soft bounce is temporary, such as a full mailbox or a busy server. Hard bounces are the bigger risk, because mailbox providers treat them as a sign of poor list quality.
Why B2B emails bounce
- People change jobs, and their old work addresses are closed.
- Companies change domains after rebrands and mergers.
- Typos from manual entry and web forms.
- Old or unverified lists that have never been checked.
- Catch-all and role addresses that behave unpredictably.
How bounces hurt you
Mailbox providers watch bounce rates, spam complaints and engagement. High bounce rates suggest you are not managing your list, so providers may filter more of your mail to spam or throttle delivery. Your email platform may also pause your account if bounce rates stay high.
How to protect deliverability
Verify before you send
Check every list for valid format, active domain and mailbox status before a campaign, and suppress invalid and high-risk addresses. See data append and verification.
Authenticate your domain
Set up SPF, DKIM and DMARC so mailbox providers can confirm your emails are genuine.
Warm up new domains and mailboxes
Start with low volumes and increase gradually.
Send relevant messages
Targeted, useful emails get opened and replied to, which builds a positive reputation. Generic blasts do the opposite.
Make opting out easy
A clear unsubscribe link reduces spam complaints, which hurt reputation more than unsubscribes.
Clean your lists regularly
Remove hard bounces immediately and schedule regular data cleansing.
Start with better data
Deliverability problems often start with the list itself. Verified, up-to-date contacts give every campaign a better chance of reaching the inbox.
Frequently asked questions
What is a good bounce rate for B2B email?
Lower is always better. Many email platforms flag accounts when bounce rates rise above a few percent, so verify lists before sending.
Does verifying a list guarantee inbox placement?
No. Verification removes invalid addresses, but inbox placement also depends on authentication, content, sending patterns and engagement.