iis smtp nntp: Hi ,

I want to develop a solution in which all of the mails with attachment
will undergo a minor change i.e i will add some kind of watermarking.

For that i want to develop some kind of smtp proxy server which will
do the work of watermarking , further it will forward the mail to
actual smtp server.

Any pointers related to development of proxy server would be really
helpful.


Rgds,
Raan

[quoted text, click to view]

I don't see any reason to embark on standalone SMTP proxy server
development to do this (not to mention that this list is dedicated to
operating and extending an already robust SMTP server, rather than
building separate products).

In-transit file detachment, modification, and reattachment would be
very appropriate to do using a Transport Event Sink (Google this).

Transport Event Sinks capture a message after it has been received
over SMTP, but before it is relayed to a destination server or
delivered to a user mailbox. It's the ideal time to make such message
mods without getting involved in proxying the SMTP conversation. A
large variety of languages can be used to develop such sinks, even
VBScript, with the main difference being scaleability (as opposed to
functionality).

One would typically use/build a content scanning proxy if you needed
to reject certain message content during the initial convo (a quite
common goal for anti-spam/anti-virus purposes, but apparently not for
yours), and your actual SMTP server couldn't do this. If you're going
to deliver all the mail after modification, then extending your MTA is
a much more reasonable project.

--Sandy


------------------------------------
Sanford Whiteman, Chief Technologist
Broadleaf Systems, a division of
Cypress Integrated Systems, Inc.