Problems with qmail

[split]

Hello,

I see in logs, a lot of records like this:

delivery 469: deferral: Connected_to_4.79.181.14_but_connection_died._(#4.4.2)/

with different remote servers and destinations.
In one of those remote servers, I see in log:

lost connection after CONNECT from ...

Any idea why is happening this?

Thanks.
split.