HDD guardian is best SMART monitor for windows. One of killer feature is mail notification. It's work good, bur only if mail-server is certificated. If you have internal mail server for administrative purpose then that server is self-signed because work
only for local net. In this case HDD Guardian can't send any message. The trouble is in self-signed mail-server certificate. I try install certificate as trusted, but windows not approve them in test .NET program. It's simple program for send message thru
I see the solution of that problem as investigate right method of install server-certificate in windows or show request window with approve current server-certificate with install certificate in program provided directory as that doing in test program.
And please make the "Send test email" as "button" NOT "link".
Also will be perfect make window with debug messages of sending mail with "Ok"/"Fail" state message. Because if mail-server you own - it's Ok, but if it not you own (server of provider) you can't make debug logging at server-side. Not arrived
e-mail message only states that something not work, but what you can't know.