Hard Bounce Failures

Hard bounce failures occur when email messages can never be delivered. These failures can occur for multiple reasons, such as address errors, bad domain names, unknown users, and closed accounts. To ensure a positive sender reputation, our system automatically suppresses email addresses that return hard bounces from future mailings.

An email message may return a hard bounce failure if the email address is valid but the domain does not exist. This typically indicates that the account has been closed for some time. A hard bounce of Unknown User may indicate one of several conditions.

  • Your mailing list may contain a high number of undeliverable records because it has not been mailed to recently or too much time as passed between the list capture and the mailing. This is one of the main reasons by some major mailbox providers block incoming email. We recommend you adjust your mail frequency for customer preference and value and review all segments of the list on a regular basis to ensure brand visibility, the continuity of communication, and address delivery. To reduce the likelihood of a complaint, set standards to send first communications within five to 10 days after data capture. If you're mailing to an "old" segment, deploy the mailing slowly to avoid spikes in Unknown User failures.

  • You may not adequately validate email addresses during data capture. We recommend you send follow-up email to new recipients to confirm opt-in permission and validate delivery to the address. If email bounces for reasons that indicate an invalid or inactive email account, remove the address and contact the recipient for new or updated email address information. To minimize typographical errors, we recommend you require double-entry of email addresses during online registration or opt-in. We also recommend you perform address hygiene to correct common misspellings on major domains before you add large quantities of addresses to your list and then send a confirmation email to corrected addresses.

  • For a high incidence of stale, inaccurate, or fictitious data, you may have unreliable data sources such as from a list rental or affiliate. We recommend you investigate the data compilation and management practices of your data sources and confirm consent and delivery before you add third-party names to a list. We also recommend you contact recipients for new or updated email address information and perform address hygiene to correct common misspellings on major domains before you add large quantities of addresses to your list, then end a confirmation email to corrected addresses.

An email message may return a hard bounce failure if the email address has a domain that is invalid or does not exist. A hard bounce of Bad Domain may indicate one of several conditions.

  • Your mailing list may contain a high number of undeliverable records because it has not been mailed to recently or too much time as passed between the list capture and the mailing. This is one of the main reasons by some major mailbox providers block incoming email. We recommend you adjust your mail frequency for customer preference and value and review all segments of the list on a regular basis to ensure brand visibility, the continuity of communication, and address delivery. To reduce the likelihood of a complaint, set standards to send first communications within five to 10 days after data capture. If you're mailing to an "old" segment, deploy the mailing slowly to avoid spikes in Unknown User failures.

  • You may not adequately validate email addresses during data capture. We recommend you send follow-up email to new recipients to confirm opt-in permission and validate delivery to the address. If email bounces for reasons that indicate an invalid or inactive email account, remove the address and contact the recipient for new or updated email address information. To minimize typographical errors, we recommend you require double-entry of email addresses during online registration or opt-in. We also recommend you perform address hygiene to correct common misspellings on major domains before you add large quantities of addresses to your list and then send a confirmation email to corrected addresses.

  • For a high incidence of stale, inaccurate, or fictitious data, you may have unreliable data sources such as from a list rental or affiliate. We recommend you investigate the data compilation and management practices of your data sources and confirm consent and delivery before you add third-party names to a list. We also recommend you contact recipients for new or updated email address information and perform address hygiene to correct common misspellings on major domains before you add large quantities of addresses to your list, then end a confirmation email to corrected addresses.

An email message may return a hard bounce failure if the email address has a format or syntax error, such multiple or missing "@" sign. A hard bounce of Address Error may indicate one of several conditions.

  • You may not adequately validate email addresses during data capture. We recommend you send follow-up email to new recipients to confirm opt-in permission and validate delivery to the address. If email bounces for reasons that indicate an invalid or inactive email account, remove the address and contact the recipient for new or updated email address information. To minimize typographical errors, we recommend you require double-entry of email addresses during online registration or opt-in. We also recommend you perform address hygiene to correct common misspellings on major domains before you add large quantities of addresses to your list and then send a confirmation email to corrected addresses.

  • For a high incidence of stale, inaccurate, or fictitious data, you may have unreliable data sources such as from a list rental or affiliate. We recommend you investigate the data compilation and management practices of your data sources and confirm consent and delivery before you add third-party names to a list. We also recommend you contact recipients for new or updated email address information and perform address hygiene to correct common misspellings on major domains before you add large quantities of addresses to your list, then end a confirmation email to corrected addresses.

An email message may return a hard bounce failure if the email address is valid for the domain but is now closed or suspended. A hard bounce of Closed Account may indicate one of several conditions.

  • The recipient may have changed the email address. You should contact the recipient for new or updated email address information. As a best practice, we recommend you maintain good list hygiene and mailing practices and request new or additional email addresses from its recipients as part of its data capture and ongoing communications.

  • For a high incidence of stale, inaccurate, or fictitious data, you may have unreliable data sources such as from a list rental or affiliate. We recommend you investigate the data compilation and management practices of your data sources and confirm consent and delivery before you add third-party names to a list. We also recommend you contact recipients for new or updated email address information and perform address hygiene to correct common misspellings on major domains before you add large quantities of addresses to your list, then end a confirmation email to corrected addresses.