[Exim] SMTP error from remote mailer after LHLO

Hi :

I am running Exim 3.36-140 (with cpanel) and recently I am getting this
error time by time . By example :

2003-05-07 15:08:04 19DOeS-0007dI-00 ** xxxxxx@??? R=lookuphost
T=remote_smtp: SMTP error from remote mailer after LHLO xxx.xxxxxxxx.com:
host mx2.hotmail.com [65.54.166.230]: 500 Unrecognized command

LHLO is LMTP, and I don´t understand why Exim use LHLO instead EHLO
sometimes ... Each 7 days or more, certain messages is geting this error.

And the error is with servers like hotmail.com , yahoo.com, vodafone.net ...

Any idea ...

Thanks in advance

Jontxu