What is an email bounce?

A bounce is a response from the recipient mail server or mailbox provider telling the sender that an email was not delivered. A bounce means that the email message did not make it into the recipient’s mailbox and the message has been returned to the sender. 

Contents of a Bounce Message

From the eInsight Campaign Production Report, the hotel user can click on the hyperlink for Total Bounces and review the individual bounce messages. Usually, the bounce message will provide valuable information to help identify the cause of the delivery failure. The bounce message can include:

• The time and date the message bounced
• The mail server that bounced it
• The RFC code and reason for the bounce (According to the RFC, hard bounces are depicted by a 5XX code and soft bounces by a 4XX code; however, not all ISPs adhere to that code consistently, so there could be exceptions to this rule.)

Soft Bounce vs. Hard Bounce

There are two types of bounces, Soft and Hard. Think of soft bounces as blocks that are a short-term issue; the hotel does not need to permanently remove these from the database. However, hard bounces are either invalid or non-existent addresses that should be removed immediately. eInsight will flag all Hard Bounce emails and will prevent these emails from being included in future campaigns via the Campaign Audience criteria.

Soft bounce

A soft bounce means that the email address was valid, and the email message reached the recipient’s mail server. However, the message bounced and did not get delivered. Common soft bounce reasons include:

• The mailbox was full (the user is over their quota)
• The server was down
• The message was too large for the recipient’s inbox
• The sender has reputation issues
• The content of the email is suspicious, seen as spam

eInsight's email service provider, Twilio SendGrid, will continue to attempt to send these soft bounce messages for up to 72-hours until the message is delivered. If a message is continuously bounced, then eInsight will mark it as a soft bounce. The email address remains in the eInsight database, and the hotel can later include the soft bounced email in another future campaign audience.

Hard bounce

A hard bounce occurs when the message has been permanently rejected either because:

• The email address is invalid
• The email address doesn't exist

eInsight will mark these email addresses as a Hard Bounce and will never include the email in a future campaign audience. Continuing to try to send to a known bad address will harm a hotel's IP/Domain reputation with the receiver, so the eInsight CRM prevents such action.

How can a hotel improve the bounce rate?

Cendyn recommends a bounce rate lower than 2%. The best way to reduce the number of bounces is by following key email deliverability best practices. This includes the following:

• Maintain good list hygiene: Hotels should purge their list regularly of invalid emails and non-responders. High bounce rates can affect sender reputation, so keeping a database clean will go a long way to achieving higher deliverability rates. 
• Use double opt-in: Send a confirmation email when users subscribe to a list. This way the hotel can ensure that the user’s email is not only valid, but that they in fact want to receive their email messages.
• Monitor email delivery: Track email deliver rates by paying close attention to bounce rates as well as click engagement. With regular monitoring, a hotel can catch potential failures before they happen or before they do too much damage.

Learn how to investigate bounces.