[ILUG] deliveries to postmaster Sendmail securiety issue

[Anthony]

> Can anyone tell me why postmaster would get bounc backs for e-mails which 
> have not been sent out?
> What kind of tests can I do to see if sendmail is no secure?

Hi Kieran,

You can check if your machine is acting as an open relay at
http://www.abuse.net/relay.html

However I'd say it's far more likely that spammers are sending emails
with the Reply-To: header set to an address at your domain. (It's a
trivial matter to set the headers of an email message.)
http://en.wikipedia.org/wiki/Backscatter#Backscatter_of_email_spam

Best wishes,
Anthony