The blacklist cache would stop repeat dictionary attackers and if you cached users who have already been LDAP authorised (and held them in memory cache for a settable time) then the load would minimal on the LDAP (or whatever) server.

Alan wrote: Hey WebGuyz, I am a bit disappointed that the new LDAP feature in SF in not used for incoming.  But I see that you have another method to do something similar.  Could you provide some assitance or script to help with your method of automatically extracting LDAP emails from Exchange.  I am being hit hart by a spammer spoofing my domain with literally tens of  thousands of bounces just over the past two days.  You can contact me via the forum private messaging if you want to keep confidential. Thanks for any help you can provide.

Alan,

  Take a look at this ADSI script below. If you can get it to work then maybe it can be modified to get a listing of Exchange mailboxes. I don't have Exchange but if its in the ballpark then maybe it can be a starting point. I can help you with the ASP, but not the Exchange testing. You may have to run this on the Exchange server.(hopefully you have to have IIS on that server)

http://support.microsoft.com/?kbid=241474

Another added benefit of doing this is that these exchange users can now log into the quarantine db with their own login/password to manage their own filtered mail. Most know to check once a day and we keep it for 48 hours.

We also have these exchange users use us as a smarthost so that we could get a list of everyones outgoing emails (as well as our local users) . We add to the AutoWhitelistDelivery.txt any emails that our valid customers send out. We do this with scripts we wrote to poll our dedicated outgoing mail server every 10 minutes and create valid SENDER|RECEIVER pairs for all emails that are sent out. The premise being that if they are sending an email they must be wanting a reply back.

Our AutoWhitelistDelivery.txt file is 1.3 meg big right now and has about 28,000 entries. This has cut down false positives down dramatically!!

Well for now all the customers are also customers whom I manage their exchange server so it's not a big deal for billing, however that is an interesting way to look after billing! Currently we do email based entirely on domains, which has been successful, it is based on the honor system as far as billing goes.

We have 3 customers who have Exchange servers and we provide relay services for. We wrote a web interface that allows their admin to enter their users login/pasword info into a table and have a script that polls that info every 10 minutes (same script as mentioned above) and also adds that to the AuthorizedTo list. This is helpful to us because we charge per user per month. Customers don't bug us every time they want to add or remove a user, they just update it themselves and in 10 minutes its active. We run a report of these users at the end of the month and bill accordingly.

For those who relay for others, do you just charge a flat fee per month??