Cannot Send Email From My Application

I can’t send emails from my local application using SMTP connection.
I tried to directly connect to SMTP server port 25, it always fails. I tried using telnet to access port 25.

I see that McAfee suddenly break connection. The action is perceived as dangerous by McAfee.

I checked McAfee log and found this statement :
01/06/2015 9:00:23 AM Blocked by port blocking rule C:\Windows\system32\telnet.exe Antivirus Standard Protection: Prevent mass mailing worms from sending mail XXX.XX.XX.XX: 25

It’s clear now, that McAfee blocked telnet.exe port 25, we need to add the application to McAfee exclude list.

  • Right click on the tray McAfee icon, click on Manage Features“, “VirusScan Enterprise“.


  • Right click on the Access Protection then choose Properties.


  • Click on Anti-virus Standard Protection and “Prevent mass mailing worms from sending mail“, then click on Edit button.


  • Next step, add telnet.exe and other file that we want to exclude.


It’s done….!