Account doesn't exist: 59
Domain does not exist: 0
38 Soft Bounces
Mailbox was full: 23
Remote mail timeout: 15
Remote server busy: 0
Spam trapped: 0
Black listed: 0
"Hard Bounces" are permanent failures, so it's recommended you call those to obtain a new address.
E-mail addresses that bounce will be automatically filtered out of future sends, depending on how they bounce.