What are the most common causes of soft bounces?

Soft bounces result from temporary conditions that may resolve:

Mailbox conditions:

Mailbox full: User has exceeded quota. Mailbox temporarily unavailable: Maintenance or issues.

Server conditions:

Server busy: High load, try again. Service temporarily unavailable: Maintenance or outage.

Sending-side limits:

Rate limiting: Sending too fast. Too many connections: Connection limit reached.

Spam prevention:

Greylisting: Intentional delay for unknown senders.

Technical issues:

DNS timeout: Temporary lookup failure. Connection timeout: Network latency.

Response to soft bounces:

Retry according to schedule. Monitor for patterns. Convert to hard after persistent failure.

Soft bounces are temporary obstacles. Patience and retry usually resolve them.