A soft bounce happens when a recipient’s email server temporarily rejects your email because the subscriber’s inbox is full, their email server is down, or their email account is on hold. This can happen due to several reasons, including:
- Invalid email address or sending domain
- A message exceeds the size limits set by the recipient’s mail server
- A high volume of emails sent to the same recipient in a short period
- Email being flagged as spam by a content filter
- Missing DNS records for the sender’s domain
- Poor sender reputation due to previous email bounces or spam complaints
If you’re using certain marketing automation platforms and a soft bounce happens more than 3 times, they’ll be converted to a hard bounce i.e., the recipient will be removed from your email list. But unlike hard bounces, which indicate permanent delivery failures, soft bounces are often temporary and can be resolved.
How to prevent soft bounces
Use these strategies to prevent soft bounces and improve your email deliverability:
- Optimize content and size: Avoid link shorteners, balance text and images, and keep emails under 110KB to prevent rejections due to content issues.
- Manage sending frequency: Gradually ramp up your sending volume and reduce the number of emails sent to specific mailbox providers if rejections occur.
- Check sender and DNS records: Ensure your sender address is valid and all necessary DNS records (SPF, DKIM, DMARC) are in place to maintain deliverability.
- Improve sender reputation: Track deliverability metrics and reevaluate sunsetting windows. If need be, temporarily suppress inactive segments to maintain a strong sender reputation.
With a marketing automation platform like Klaviyo, you can easily check and reduce bounce rates.
Sign up for Klaviyo and get detailed reporting on soft bounces to improve your email deliverability.