Re: [swinog] UPC Mailservers problems with greylisting

Benoit Panizzon wrote:

Hi Per

...

Is there any point in greylisting genuine mailservers? We only greylist dodgy-looking setups.

True, no point in greylisting a propper SMTP engine that does queueing and would resend the email later in case of a 4XX error.

But how do you find out which ip's to greylist and which not to?

Hi Benoit, as I wrote yesterday, we use a fairly simple set of regex patterns to look at the reverse mapping of the server address, plus another simple set of criteria for e.g. the HELO. I'll be happy to share them with everyone.