[Mailman-Users] Best way to slow down all the spam to my lists?

[Richard Damon]

On 12/14/19 4:29 PM, Keith Seyffarth wrote:
> Grant Taylor via Mailman-Users <mailman-users at python.org> writes:
>
>> On 12/13/19 9:02 PM, Mark Sapiro wrote:
>>> As postgrey learns, it will remember triplets (sender, sending IP, 
>>> recipient) and not delay them and in addition will whitelist domains 
>>> that retry successfully more than a few times.
>> The bigger senders are doing things now (more than ever) that they 
>> weren't doing 15+ years ago.  Now farms of servers will try to contact 
>> you.  The message may first try from one IP, then from another IP, then 
>> from a 3rd....  It may eventually try from the same IP and make it through.
>>
>> I think most grey list solutions have an option to specify the network 
>> (frequently configured a a /24) for the sending IP.  This significantly 
>> helps with different servers in the same server farm trying to resend 
>> messages.
> Some greylisting solutions also allow you to whitelist a domain or
> subdomain, but this can result in spammers spoofing that domain getting
> through...
>
> Keith
>
>
Unless you only whitelist domains which use SPF, then SPF will catch the
spoofers.

-- 
Richard Damon