Author: Dean Brooks Date: To: exim-users Subject: Re: [exim] host use tsl on port 25?
On Tue, Jan 23, 2007 at 02:45:00PM -0500, Walt Reed wrote: > On Tue, Jan 23, 2007 at 01:47:07PM -0500, Dean Brooks said: > Again, this is why I had qualified my statement to specifying a
> "moderate" level of traffic. Obviously if you are running your servers
> nailed to the wall (barely keeping up with normal levels of traffic,)
> any little thing you do that extends transaction times or increases
> system load in the slightest way will have a major impact. I would also
> expect that any organization running servers at that level already has
> plans to resolve that problem (or is on the verge of bankruptcy.)
You are missing my point I'm afraid. I'm not referring to servers
that are pushed near their available capacity. I'm talking about
servers that simply handle a high-volume of email.
If you are handling 20 to 30 deliveries per second, adding TLS
negotiations to each outbound connection can make a profound
difference in load. Trust me, we've ran into that before and it
is unbelievable how much overhead TLS adds. Not sure if it was
OpenSSL that was the culprit or just the number-crunching, but it's
a real concern.
