'Today' considers data retention and IMP

[Chris Edwards]

On Tue, 13 Jan 2009, John Lamb wrote:

| If you were going to MitM SMTP connections, wouldn't it be easier to
| force plaintext rather than spoof certificates? It would also have the
| benefit of looking more like an innocuous configuration error rather
| than an evil interception.

I simply meant to introduce a transparent proxy for SMTP on port 25, 
offering STARTTLS with a self-signed certificate.  But you're probably 
right - simply not offering STARTTLS at all would likely be easier.

Both would be detected by Ian's canaries, and would completely break those 
(few?) cooperating sites that _do_ check certificates.

So it would seem unlikely the IMP black boxes would do this, and hence 
opportunistic TLS would seem sufficient to protect server<->server SMTP.
As has been noted, many systems now do this out of the box.