Soft Bounce
A soft bounce is an email that the receiving server temporarily rejects for a transient reason, a full mailbox, a message that's too large, or a server that's briefly down. Because the failure is temporary, the address is still valid and the message may be delivered on a later retry rather than being permanently undeliverable.
Most email platforms automatically retry soft bounces over a set window before giving up. If an address keeps soft bouncing across multiple campaigns, many tools eventually reclassify it as a hard bounce and suppress it, since persistent failures look like a dead mailbox to providers.
The pitfall is ignoring a rising soft bounce rate; it can foreshadow deliverability trouble or list decay even though no single bounce is permanent. Contrast it with a hard bounce, which is final. Related terms include email deliverability and hard bounce.
Last updated: 14 June 2026