Other - Blocking email on Port 25

Hi Guys,

Sorry, this probably isn't the best place to post this - feel free to move it to a more relevant place - but I was hoping that there is an element of discussion involved.

My problem is that I am trying to create a program which searches a database and checks whether records have been updated within 10 days of creation. If they haven't, an automatic email is sent to the person who created the record to remind them to update it. The program is written in VB6 and the logic which constructs the automatic emails works perfectly. The problem I have is that when the program trys to send the emails out, I get the following error message:

"The message could not be sent to the SMTP server. The transport error code was 0x800ccc15. The server response was not available."

I have Googled this error and discovered that my anti-virus software (McAfee VirusScan Enterprise 8.0.0) is blocking the program from sending email using Port 25. If I go into my anti-virus console and disable the block on Port 25 the program works like a dream, but if I then try and run the program again, the port has been re-blocked.

Firstly, can anyone tell me if there is a way of constantly enabling the sending of email on Port 25?

Secondly, I'd be interested to hear your views on whether it is a good idea to do this. I am sitting behind a firewall in work, but if I was to do this on my home PC, would it be a security risk?

Any help or discussion appreciated.

If this is a Windows PC, we could move this to the Windows Security forum. Nilpo can probably give you an educated answer on the topic. With most firewall programs, you can configure rules to allow traffic on specific ports and you can determine the protocol to be used and the direction of traffic (inbound, outbound or both). You can also setup access for specific applications running on the computer. I don't see a huge risk in allowing this specific application to open the port and send out an e-mail message. I would wait for a few more opinions before taking action on this, though

Thank you for the reply JMH, it is a Windows PC so feel free to move it to the Windows Security Forum if you wish.

I like your suggestion of opening and closing the port from within the application, I guess this would minimise any risk.

But I would appreciate several different opinions.

Thanks again.

--->Moved to Windows Security forum

I would definitely get more opinions on the matter. Perhaps someone can explain to you what is actually happening when the port is open. I think if you set it up for the specific applcation, then even if the port is "open" it's only open for that specific application.

You probably can find the answer from McAfee. Most AV outgoing mail scanners create a "proxy" on your computer that intercepts port 25 from an application, scans the outgoing email, then forwards it along. Sometimes this will make your final smtp server reject the message. For some VB email apps I've done the easiest cure was to disable outgoing email scanning in Norton AV.