How many times should my system retry sending after a soft bounce?

Retry count depends on your strategy and risk tolerance:

Industry standards:

Minimum: 3-5 retries. Typical: 8-15 retries. Maximum window: 24-72 hours total.

Factors affecting retry count:

Bounce type: Mailbox full may need more retries than server busy. Message urgency: Time-sensitive content may warrant shorter windows. Resource constraints: Queue management capacity.

Typical configuration:

First retry: 5-15 minutes. Subsequent: Exponential backoff. Max attempts: 10-15. Max time: 48-72 hours.

When to stop:

After max retries with no success. If error converts to 5xx. After max time window expires.

Persistence has limits. Give temporary issues time to resolve, then accept failure.