The SMTP filter API provides services for accessing SMTP messages processed by the WinGate SMTP server. You access and modify SMTP messages and data as they progress through the SMTP chain.
Message Filtering
You register an SMTP filter with a call to SMTPQueueRegisterProcessor. In this call you provide a SMTPQueueProcessorProviderInterface for the framework to call you to process commands, responses, data and manage lifetime management of your filter.