[exim] Errors in smtp transactions ?

Hi

First post so please be gentle :)

I have a very occasional problem of servers complaining about my server

being impolite, about 10 times a day with a volume of about 10000 mails
a day. I am running exim 4.32. I get the following from a few sites.

503 5.0.0 Polite people say HELO first
503 Bad Sequence, polite people say HELO first

There is no common mail server its sendmail, postfix, mailmarshal,
exchange and other stuff i dont recognise SLMail pro ?

When telneting to them they all seem to give a 503 or 502 error on EHLO.
but seem to be happy with a HELO domain.name.name after that.

Is there a way to log the smtp transaction to certain domains ? I can
only assume it is either due to bandwidth problems or after a EHLO my
system is not setup to do HELO, although i would assume that is normal ?
Am i right ?

At other times to the same servers all is fine. This is probably nothing
but i would be happier knowing the reason for it.

Thanks
Sean