Milter-greylist

A while ago I was suggested to use 'helo not "%d"' constructs
to verify if DNS PTR and HELO names of a remote relay agree.
Unfortunately, either I do something wrong, or it misfires
too often. With a config snippet like this:

racl continue \
     not helo "%d" \
     set $dnsscore+=10 \
     log "(%i SP:+10) %P{conninfo}: Malformed HELO (HELO '%h' does not 
match reverse DNS '%d')" \
     set $msgDNS="Malformed HELO (HELO '%h' does not match reverse DNS 
'%d')"


... I often see logs like these, which (seem to) mention the
same string in both HELO and DNSPTR parts:

Aug 29 01:06:14 dao.virt.cos.ru milter-greylist: [ID 536703 mail.info] 
(216.227.218.80 SP:+10) IP:'216.227.218.80' DOMAIN:'joy.lunarbreeze.com' 
HELO:'joy.lunarbreeze.com' FROM:'gVIwyErHMkoOi@...' 
RCPT:'bugaev@...': Malformed HELO (HELO 'joy.lunarbreeze.com' does 
not match reverse DNS 'joy.lunarbreeze.com')

...and I can't find any mismatches in real DNS (perhaps dot-ended
names, etc.) Any ideas on debugging this issue?
NOTE: Okay, the example above is a spammer example, but I have
such issues with big-name providers as well which are unlikely to
be lax in their DNS setups. Their logs rolled off-screen at the
moment ;(


..These are possibly more reasonable "mismatches", as far as
case-sensitivity might be concerned (although not really
relevant for DNS):

Aug 29 04:57:51 dao sendmail[19426]: [ID 801593 mail.notice] 
s7O0vmQv019426: MGL-TEMPFAIL-DNS-120: DNScheck: likely spam-source; 
repost from registered SMTP server, or contact 
bypass-antispam@.... Malformed HELO (HELO 
'DUB004-OMC1S3.hotmail.com' does not match reverse DNS 
'dub004-omc1s3.hotmail.com') SPF pass


...And these are proper hits that the rule is made for:

Aug 29 00:38:09 relay-mta milter-greylist: [ID 354941 mail.info] 
(89.240.10.108 SP:+10) IP:'89.240.10.108' 
DOMAIN:'host-89-240-10-108.static.as13285.net' 
HELO:'mail.netcellsolutions.com' FROM:'gzivhsom@...' 
RCPT:'hel@...': Malformed HELO (HELO 'mail.netcellsolutions.com' does 
not match reverse DNS 'host-89-240-10-108.static.as13285.net')



Thanks,
Jim Klimov