[exim] SMTP connection lost

Hi there.

I constantly receive errors with some servers and can't accept or send
mail to them.
In log this looks like:

SMTP connection from forward14.mail.yandex.net [95.108.130.92] lost while
reading message data (header)

This results in two porblems (maybe more):
1) I cannot send to servers, who have sender callout verification enabled
(if they are in problem group)
2) I cannot receive messages from servers in problem group

I've read lots of forums about that problem.
First, I must say that lots of logs posted to forums contatin that same
Yandex servers.
Second, I've tried to change my MTU and disable DNS checks - still no
success.
Third, the traceroute to the server mentioned looks quite strange - it is
not traceable form my server, but it's ok from my home PC.
It seems to be blocking ICMP from some network, and AFAIK this can cause
MTU traceback not working. But, is Exim trying to make MTU trace?
If it is, is there any way to avoid that for some hostlist?

Any thoughts about this would be much appreciated.

P.S. atm I don't have any tcpdump log, but as soon as Yandex' MTA retries
I'll get it and post here if needed.