Why do emails bounce back?
An email bounce simply happens when the email message sent by you doesn’t deliver. If this happens, the mailer will receive automatic notification of the delivery failure. This failure starts with the recipient’s mail server for several reasons.
Reasons for a Bounce Message
Normally, the bounce message will provide you helpful information to help you identify the reason for the email delivery failure. This includes the following:
- The time and date when the message bounced
- The mail server by which it got bounced
- As claimed by the RFC, hard bounces are drawn by a 5XX code and soft bounces by a 4XX code. Though not all ISPs adhere to that code consistently, so there could be limitations to this rule.
Soft Bounce vs. Hard Bounce
There are two types of bounces that you can get, a soft bounce/block or a hard bounce. Consider Soft Bounces as blocks that are a short term issue, you don’t require to permanently take these addresses off of your list. But, Hard Bounces are either invalid or non-existent addresses that should be eliminated immediately.
In addition to this, a soft bounce indicates that the email address was valid and the email message reached the recipient’s mail server. Still, general reasons it bounced back involve:
- The mailbox was full of the user
- The server was down
- The message was too big for the recipient’s inbox