[exim] dot at the end of domain

Hi.
That's what I see in logs:

rejected after DATA: domain missing or malformed: failing address in "To"
header is: XXX@???.

i.e. '.' at the end of domain-part leeds to this error.
But 'domain-part.' such a 'dill.nov.net.' is right address, isn't it?
Or is there RFC about it?

PS. sorry for bad english :)

--
wbr, Golovanoff Sergio
sergio@???