System requirements are mostly engineering level requirements. They put constraints on how the component should be engineered.
| ID || Description || Release || Priority || Status|
| S-1 || Threading model that avoids context switches for outbound SMTP interactions || Kenai ||Priority || Not done|
| S-2 || Routing of inbound messages to particular operations based on SMTP-specific feature. This is a similar requirement to something like the SOAP Action URI. || || P2 || Not done|
| S-3 || Full internationalization of all logging and error messages || Kenai || P1|
| S-4 || Full Junit tests for all classes || || P1|