Because Blackbaud NetCommunity\Online Campus Community (OCC) uses simple mail transport protocol (SMTP) to deliver messages, bounce messages and codes are simply reported to the software and not generated by it.  

Most internet and email service providers will customize their outgoing bounce messages to conform to their network's terms of service, however SMTP email has a standard set of codes in use across the entire internet, globally.

For example:
Suppose you attempt to send a message to an address that does not exist.  


ISP #1 may send a message of
Remote-MTA: dns; smtp.store.example [192.0.2.3]
Diagnostic-Code: smtp; 550 No such user here
While ISP #2 may send a message of 
while talking to smtp.store.example [192.0.2.3]
>>> RCPT TO:<nonexistinguser@store.example>
<<< 550 No such user here
There are many SMTP bounce codes.  The vast majority of mainstream internet and email service providers maintain a list of their codes and messages with meanings.  Below are some links to a random sampling of some ISPs bounce codes and messages. If you would like to know what a hard bounce is, please see  What is a hard undeliverable email (hard bounce)?
If you would like to know what a soft bounce is, please What is a soft undeliverable email (soft bounce)?.

Note: We provide links to third-party websites in an effort to help you resolve your issue. We are not responsible for the information on third-party websites, and we cannot assist in implementing the solution on these websites.