To verify e-mails when port 25 is blocked, you have use a proxy server.
Proxy server is a program that allows LAN users to work with Internet (when only one machine has the "real" IP address).
To specify a proxy server connection:
1. On the Tools menu, click Options
2. Select the Proxy Settings tab
3. Check Enable proxy.
4. Specify the server IP Address and Port Number. Usually, it is 1080. Don't confuse Socks proxy with http and ftp proxies, which are on 3128 (8080) and 3121 ports by default. Smart Email Verifier does not work through http or ftp proxies.
If your proxy server requires authentication then check the Proxy Server requires authentication check box. Specify the login and password.
Click OK to confirm.