OT - Outbound mail server integrated with FTP

Logan Shaw lshaw at emitinc.com
Mon Aug 14 22:52:51 IST 2006

On Mon, 14 Aug 2006, John Schmerold wrote:
> I'm looking for a solution to the problem of large (often duplicated) email 
> attachments. It seems to me that a simple solution to the problem is to have 
> a specially configured outbound mail server that detaches attachments from 
> any email greater than 50K, generates an ftp account and inerts a message at 
> top of the email saying "go to ftp://un:pw@ftpserver.com for attachment 
> referenced in this email.
> If the server was really smart, it would generate a CRC of each outbound 
> attachment so duplicates could be stored as one file.

I believe some versions of Lotus Notes used to do this, or so
a friend of mine (who was a big Notes advocate) used to say.
But, it only did it within the intranet.  Still, could be
valuable within a large corporation.

My general thoughts on this idea are:
1)  Breaks PGP, S/MIME, and anything else that signs message content
     (at least things that sign content at the MUA stage of things).
     This could be fixed if you're willing to change SMTP and let
     the MUA send attachments out of band (of the message body).
2)  Breaks the ability to take your laptop somewhere with internet
     access in the airport lounge, download your e-mail, and run,
     and know that you got everything.  Or at least it would until
     it were widespread enough that mail clients could be set up
     to fetch attachments automatically.
3)  Makes firewall issues more complex, because delivery mechanisms
     for attachments are different than for the messages themselves.
     (Can every host your mail reach also reach your server later
     to download attachments?)
4)  As a protocol, FTP sucks rocks, so avoid it like the plague.
     Use something sane, like HTTP, instead.  HTTPS might be better.
5)  Done properly, this could make it easier for users to send
     arbitrarily large attachments without causing problems.

   - Logan

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