Email bounce definition

An email bounce, also known as a non-delivery report (NDR) or a delivery status notification (DSN), is an automated response sent by an email server when an email cannot be delivered to the intended recipient's email address. This can happen for a variety of reasons, such as:

1. Invalid email address: The email address does not exist or is not valid.
2. Email address is full: The recipient's email account is full and cannot accept new messages.
3. Email server issues: The recipient's email server is down or experiencing technical difficulties.
4. Spam filter: The email is flagged as spam and blocked by the recipient's email server.
5. Domain name system (DNS) issues: The DNS settings are incorrect, preventing the email from being delivered.

When an email bounces, the sender's email server will typically send a notification to the sender's email address, providing information about the error that occurred. This notification usually includes:

1. Error code: A numerical code that indicates the reason for the bounce.
2. Error message: A descriptive message explaining the reason for the bounce.
3. Recipient's email address: The email address that could not be delivered.

Common email bounce codes include:

• 550: Requested action not taken (e.g., invalid email address)
• 552: Exceeded storage limit (e.g., email account is full)
• 553: Mailbox is not local (e.g., email address does not exist)
• 554: Transaction failed (e.g., email server issues)
• 571: User unknown (e.g., email address is not valid)

Email bounces can be caused by various factors, including:

• Typos or incorrect email addresses
• Outdated or incorrect DNS settings
• Overloaded email servers
• Spam filters or firewalls blocking emails
• Email account suspension or deletion

To resolve email bounces, you can try the following:

1. Check the recipient's email address for typos or errors.
2. Verify the recipient's email account status (e.g., is it active or suspended?).
3. Check the DNS settings for the recipient's domain.
4. Contact the recipient's email administrator or IT department for assistance.
5. Use a email verification service to validate email addresses before sending emails.