Written by Pedro Martins
Monday, 02 June 2008 10:18
Hard Bounce definition:
A delivery status message stating that the email could not be delivered to the address. A permanent fatal error message, which is sometimes called a perm fail.
Common Reasons for getting a hard bounce:
User does not exist for the given domain (e.g. there is no user named bob at example.com)
The domain does not exist (the domain nonexistantdomain.com doesn't exist)
What to do with Hard Bounces: Hard bounces should be removed from your mailing list and database / CRM system, they are addresses that may have once worked but do not work anymore. Failure to remove hard bounces can have negative effects on your deliverability.
Soft Bounce definition:
A delivery status message stating that the email could not be delivered to the address for a temporary reason. A temporary error message some times called a temp fail.
Common Reasons for getting soft bounces:
The user's mail box is full, exceeded the quota
The mail server is too busy
What to do with Soft Bounces: Soft bounces should be monitored, if an address is consistently soft bouncing you may want to remove it from your list after a few consecutive soft bounces.