steps to assign socket permission

Question

hello i write a smtp client winform (using socket connect to smtp server at port 25),and deploy it to iis by NTD (no-touch deployment),i can launch the form from the client machine,when i want to connect to the smtp server,the security exception is thrown,i know that i have not assigned the socket permission in the client side to the downloaded assembly,but i don't know how to do that,who can give me a step-by-step instruction. any help will be appreciated.