When an electronic mail message is placed in a queue, it means the message is temporarily held by a mail server instead of being immediately delivered to the recipient. This delay occurs because the server is unable to process the message for immediate delivery. An example would be a situation where an email is composed and sent, but the sender receives a notification indicating the message is awaiting processing by the mail system.
The queuing of email messages is a fundamental aspect of email delivery infrastructure, ensuring the reliable transmission of a high volume of messages. It allows mail servers to manage resources efficiently, preventing overload and maintaining system stability. Historically, queuing mechanisms were developed to address limitations in network bandwidth and processing power, contributing to the evolution of robust email communication.
