What is the default value of retry attempts before a message will hard bounce?

The default value for retry attempts before a message will hard bounce is five attempts. This means that if an email cannot be delivered, the email system will try to resend the message up to five times before it concludes that the message cannot be delivered and marks it as a hard bounce. This default setting is established to provide multiple opportunities for the email to succeed in reaching its intended recipient, which is particularly useful in cases where temporary issues, such as server unavailability or mailbox issues, may prevent initial delivery. The approach balances the desire to ensure successful communication without overwhelming either the sender or the receiving server with excessive retry attempts.