[GTM glossary](/glossary.md) Soft bounce

Sales Development & Prospecting

# Soft bounce

In short

A soft bounce is a temporary failure to deliver an email. The address exists, but something prevented delivery at that moment, such as a full mailbox, a server outage, or a message that is too large.

Unlike a hard bounce, a soft bounce does not mean the address is bad. Most email platforms retry for a period, then treat repeated soft bounces as a problem and may suppress the address.

## Common causes of soft bounces

* **Full mailbox:** The recipient's inbox is over its storage limit.
* **Server issues:** The receiving server is down or overloaded.
* **Message too large:** Big attachments can exceed limits.
* **Auto-reply or filters:** Temporary policies or greylisting can delay acceptance.

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## How to handle soft bounces

### Let the platform retry

Most tools retry a few times over a day or two. Avoid manual resends that look like spam.

### Set a limit

If an address soft bounces across several separate sends, treat it as unreliable and suppress it. Say your rule is three failed campaigns in a row; that threshold is an example, so tune it to your tool.

### Check your own content

Heavy attachments and image-laden emails raise the chance of a soft bounce. Link to files instead.

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## Why soft bounces matter for outbound

A few soft bounces are normal. A rising rate can mean stale data or a sending-reputation problem on your side. Track them next to hard bounces and replies so a trend is visible early.

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## Soft bounce vs. hard bounce

A soft bounce is temporary and may resolve. A hard bounce is permanent and needs immediate removal. A repeated soft bounce can effectively become a hard one once you stop trusting the address.

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## Soft bounce FAQs

**What is a soft bounce in email?**

A soft bounce is a temporary email delivery failure. The address is valid, but the message could not be delivered at that moment because of something like a full inbox, a server outage, or an oversized message.

**What causes a soft bounce?**

Common causes include a recipient mailbox that is full, a temporarily unavailable receiving server, a message or attachment that is too large, and temporary filtering such as greylisting. These conditions often clear without any action from the sender.

**Should you resend after a soft bounce?**

Usually your email platform retries automatically for a limited period. Avoid repeated manual resends. If an address keeps soft bouncing across several separate campaigns, suppress it or verify it before sending again.

**Do soft bounces hurt sender reputation?**

Occasional soft bounces have little effect, but a persistently high rate can suggest poor list quality and may influence how mailbox providers treat your mail. Monitor them alongside hard bounces and clean lists regularly.

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## More related phrases

* [Domain warmup](/glossary/domain-warmup.md)
* [Email service provider](/glossary/email-service-provider.md)
* [Reply rate](/glossary/reply-rate.md)

## Similar phrases

* [Bounce rate](/glossary/bounce-rate.md)  
Bounce rate is the percentage of sent emails that are rejected by the recipient's mail server and never reach an inbox, split into hard and soft bounces.
* [Email bounce rate](/glossary/email-bounce-rate.md)  
Email bounce rate is the percentage of sent emails that are not delivered to the recipient, and it signals list quality and sender health.
* [Email deliverability](/glossary/email-deliverability.md)  
Email deliverability is your ability to get emails into recipients’ inboxes instead of spam or being rejected, shaped by reputation, authentication, and content.
* [Email verification](/glossary/email-verification.md)  
Email verification tests whether a specific email address is likely to accept mail, helping teams cut bounces, protect sender reputation, and avoid wasting outreach on dead addresses.
* [Hard bounce](/glossary/hard-bounce.md)  
A hard bounce is a permanent email delivery failure, usually caused by an invalid address or domain, and it should trigger immediate removal of that address from your sending lists.