We are using Thingworx 188.8.131.52 version.
Yes, thingworx server is behind proxy but same as when I am running the java program.
Mailserver haven't worked for me yet and I haven't upgraded my thingworx.
I have used "MailandSQLExtensions" plugin to add mailserver functionality.
And I am not able to find any other version download for mailserver API.
Thanks a lot for your help!