[Greylist-users] Re: Greylist implementation for diskless firewall
appliances
richard at stardate.ca
richard at stardate.ca
Mon Aug 25 00:16:44 PDT 2003
> One potential use of greylisting I've been thinking about
> to implement it on a firewall appliance that has an SMTP
> proxy. This enhances network security and reduces load
> on mail servers from inbound spam.
> Some questions for the list:
>
> How large is the SQL database likely to get? Would
> it be feasible to use a RAM based list without a proper
> SQL database? Has anyone worked out a formula
> for the size based on users/mail rate?
That depends on the number of users and the number of emails they get
from different people. I think the best any one can tell you is that it
will get as big as it has to.
> What issues would be created by periodically saving
> a host copy of a RAM based list which could be retrieved
> by the appliance on a cold start? One problem which comes
> to mind is somehow retrieving a stale list. The other is the
> frequency of saves needed in order for the stored copy
> of the database to be fresh enough to be useful.
Would it be possible to map drive space on a separate server and store
the databases there?
> Is greylisting likely to cause loading issues due to retries?
Yes but a little DLINK firewall will handle a lot of throughput. I think
you are talking about something a little more substantial.
> I realize it's still early in this implementation but I thought it
> might be worth raising these issues now. A smart appliance
> based implementation of this concept could easily increase
> the number of people using greylisting overnight to many
> thousands of MTA's.
The down side is that this would make the spammers sit up, notice and
take evasive action.
More information about the Greylist-users
mailing list