com.openexchange.mail.transport.TransportProvider has been extended by method:
/**
* Gets a newly created {@link MailTransport} instance, that can be used to
* send mails via the configured no-reply address.
*
* @param contextId The context ID
* @return The transport
* @throws OXException
*/
public abstract MailTransport createNewNoReplyTransport(int contextId) throws OXException;

This method sends out messages via a configured no-reply transport account .The default transport implementation for SMTP has been extended by a proper com.openexchange.mail.transport.MailTransport implementation that utilizes the SMTP account and properties configured in noreply.properties (see related SCR https://wf.open-xchange.com/webswamp/swamp/template/DisplayWorkflow.vm/workflowid/2230). The defined properties can be overriden per context via ConfigCascade, e.g. to define separate sender-addresses for different domain names.