When an email is sent through an SMTP (Simple Mail Transfer Protocol) server, the server will attempt to deliver the message to the recipient’s email server. If the delivery fails, an “undeliverable” or “bounce back” message will be generated and returned to the sender’s email address.
There are a few different types of delivery errors that can occur:
1. Hard bounce: A hard bounce indicates that the recipient’s email address is invalid, non-existent, or has been deactivated. The email server will return a bounce message to the sender indicating the reason for the failure, and the message will not be retried.
1. Soft bounce: A soft bounce indicates a temporary delivery issue such as a full mailbox or a busy email server. The email will be retried several times over a period of days, and if it still cannot be delivered, a bounce message will be generated.
1. Block: In some cases, an email server may block incoming messages from a specific sender or IP address. This can happen if the sender has been flagged as a spammer or if the email violates the recipient’s email policies. The message will not be delivered, and a bounce message will be generated.
To handle delivery errors through an SMTP server, the sender should monitor their bounce messages and take appropriate action to resolve any issues. For example, if a hard bounce is received, the sender should remove the recipient’s email address from their contact list. If a soft bounce occurs, the sender may want to try resending the message at a later time. If a block is detected, the sender should investigate the cause and take steps to address any underlying issues.
