How to write an SMTP Transport Event Sink in Delphi

I dont want to sniff off the port. Unless there is no other way and even then I would probably just put my head down and do it in C++ (although I _really_ dont want to). What I want to do is the following:

1. Hook the onArrival Event Sink.
2. If any address in the recipient list matches an address in my config file, write the entire message to a file in the folder specified in my config file.
3. Bow out and let the SMTP server perform its normal processing (usually delivering the message to a POP folder, occasionally being picked up by another event sink (which I didnt write and have no source for) that handles aliasing and forwarding.

This is for an email archival system. I want to trap and copy the email at arrival because by the time it gets to my users POP folders they may pull it down with their email client and I would lose it.

I realize I could probably do what Im describing by sniffing directly off the port, but it would be alot more involved than using an event sink, and I really dont want to make this any more complicated than it has to be.
 

SMTP DOES NOT produce events like you are describing.

What you are describing is a POP3 Proxy you would write it to check the user's email account
and configure their email client to access the proxy for their email.
SpamPal does this, avail on sourceforge, written in C++.

>SMTP DOES NOT produce events like you are describing.

Im sorry but you dont know what you are talking about. I have 200 lines of source code and about 50 links to Microsoft's website that says it does... In case I was unclear I am specifically talking about Microsoft's implementation of SMTP, not SMTP in general. Im looking for information on creating a specific kind of COM event sink in Delphi. If you are not experienced with COM programming you cant help me.

Microsoft's implementation of SMTP in Exchange?

Now that's a different ball of wax.

Did you take a look at Bihn Ly's EventSink Generator?
http://www.techvanguards.com

I am using the following software:

MS Windows 2003
MS SMTP Service (built into Windows 2003)
MS POP3 Service (also built into Windows 2003)

I am not using Exchange, but the method of doing Events Sinks is identical whether or not you are running Exchange. Exchange does not implement its own SMTP Service, it uses the builtin stuff (at least since version 2000, 5.5 is a different beast altogether).

Anyway, I am familiar with using EventSinkImp, but I was hoping to find someone who had some actual working code. Ill take a look at that though.

have you checked this: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cdosys/html/_cdosys_implementing_smtp_event_sinks.asp
if nothing comes up I can try to do smtn tomorrow (am also using win2k3 smtp for myself :))

> have you checked this: http://msdn.microsoft.com/library/default.asp?
> url=/library/en-us/cdosys/html/_cdosys_implementing_smtp_event_sinks.asp
> if nothing comes up I can try to do smtn tomorrow (am also using win2k3 smtp
> for myself :))

I already know how to do this using CDO. The problem with using CDO is that 1) it is synchronous, 2) it cant be multi-threaded properly, and 3) it is very slow and very resource intensive. What Im trying to do is to implement directly against the underlying event sinks. This let you write the code in a free-threaded manner. It is also possible to do asynchronous I/O and other performance enhancements. Mainly thought I need to do it this way just to avoid the almost 2MB per message memory penalty that CDO puts on my server. I cant afford for it to gobble up so much memory (although it is rare, under certain conditions it is normal for my server to start getting 10s or 100s of inbound messages per second...).

heathprovost,

could you show us your solution?

kacor CV

Sorry, still dont have a solution. I ended up having to implement this using shell notifications (i.e. copy the file from the users mailbox using file system notification events). It works, but I would still prefer to do this another way if I could as this method potentially causes locking conflicts.