Emails bigger than 1 Mb are disconnected by yahoo.com

[paco68]

Recently I have an interesting problem with the emails that are be sending to Yahoo.com.
All emails that are bigger than 1 Mb are disconnected by yahoo.com

(deferral: Connected_to_98.137.54.237_but_connection_died._(#4.4.2)

Emails are still in queue.

The interesting part is that All emails under 1 Mb even with multiple attach files are delivered successfully.

My main IP is not blacklisted and I using Domain keys too.
I tried with Postfix and Qmail and the problem persist.
I send requesting help from Yahoo, but no answers yet.

Somebody with the same issue ?

 

[paco68]

UPDATE
I recompile Qmail http://kb.odin.com/en/1161 with outgoingip.patch, I changed main IP and with this new settings emails are started to deliver to Yahoo, but I can send emails with Outlook !

Some good ideas ?

 

[paco68]

Resolved, I changed only the qmail-remote !