Why do E-mails Bounce?
Bouncing e-mails can be very vexing, especially if you’re sending an important message that needs to be relayed immediately, but instead receive a notification letter that states that it cannot find the mailbox or the user is not found.
What is bouncing e-mail by the way?
Bouncing e-mail is the jargon of DNS or Delivery Status Notification. It is called bounced back if the e-mail has failed to reach the recipient or a failure to transfer a mail. There are two kinds of bounce, first is the hard bounce, this occurs when the recipient does not exist, the error code attached in the message is number 5 and second is the soft bounce, this happens when the inbox of the recipient is already full, message size is too large or mail server disconnects while sending, there is also the unclassified bounce, if the cause is neither a hard or a soft bounce or if the cause is unknown it counts the bounced message as unclassified. When you receive a DNS for your undelivered mail, the recipient’s server receives it before it confirms that it is explicit then, sends the sender a DNS. The bounced mail’s route is unknown it just vanishes to a black hole.
This is the work of the Simple Mail Transfer Protocol or SMTP server, a delivery protocol. If delivering a mail fails, it sends back a DNS (Delivery Status Notification) or the simple form bounced back notifying you that the mail you are trying to send is invalid. This happens when the mail cannot reach the address and is rejected by the domain recipient, a full inbox, server disconnection while sending or unclassified.
There are also plenty of email bounce software created, it bounces back emails to spammers, leading them to believe that your email address is inactive and deletes the inactive address from their mailing list, freeing your e-mail account of spammers.