There will be (T/N) smtp-sender threads activated to process N mails separately and simultaneously.
However, MAILD only generates (T/N)*2 files in \Outboxes directory instead of T files.
Smart SMTP Relay is a feature that will grant user relay permission by checking mail with POP server.
Recommend value is your PTR record of IP Address, if you didn't have PTR record, you may use your MX record instead. When raidenmaild sends mail to outside domain, it will query domain info from this DNS. If you didn't know what value you should input, please leave it blank, it will take 22.214.171.124 as default DNS.
Adv resolving means it will attempt to resolve every MX record's IP address to send mail.
This option will start the POP3 SSL service and the service port will be on 995 port.
If user wanna retrieve mail via this secured channel, he should enable corresponding option in his mail client to connect to POP3 SSL 995 port.
The features is also called POP before SMTP, you may see it in other mail server softwares. With this service, Raiden Web Mail ISAPI will be able to interact with Raiden MAILD. Attachment filter will check the attachment file name.