[ale] comcast business + mail server = static ip?

[rs at ale.spam.futz.org (Robert)]

I've just had comcast business class installed, and I want to move my
mailserver over to it. However, I'm being cheap and trying not to pay the
extra $15/mo for a static ip.  I think I've read that their dhcp addresses
rarely change.. I can monitor it, and use dns update to tweak my ip if it
changes... with a 4hour ttl, I don't expect to miss much, if any, mail if the
ip changes..

what concerns me more is that the reverse dns will be comcast's
c-x-x-x-x.hsd1.ga.comcast.net...  I know that technically reverse dns doesn't
have to match the mail server's name, but some other servers might be too
picky about it.. so I was wondering if anyone with comcast business class is
running a mailserver using their assigned dhcp address? If so, have you had
any issues?

Robert