Pesky virus

John Thompson JohnThompson at
Sat Jul 24 00:15:04 UTC 2004

James Marcinek wrote:

> I'm no expert at this but I did some reading and was under the 
> impression that people will use your mail server to send emails and that 
> there's not a lot that can be done about it. I would definitely like to 
> be proven wrong with this. The simply script something to telnet into 
> your mail port and send emails... These emails are generated from your 
> server so even setting your email to send only from your domain does not 
> protect you. Is anyone listening that could shed some more light on this?

For several years already the default behaviour for sendmail is to DENY 
relaying, so unless you explicitly changed this, the scenario you 
describe above will NOT work.

If you want to check your system for an open mail relay, try here:


-John (john at

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