custom 55x error message for specific email addresses

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Sun Java(tm) System Messaging Server 6.2-7.05 (built Sep  5 2006)
libimta.so 6.2-7.05 (built 12:18:44, Sep  5 2006)
SunOS dolly 5.10 Generic_118833-03 sun4v sparc SUNW,Sun-Fire-T200

short version: 

what's the appropriate way to block mail to a specific email address
with a custom 55x error message? i know how to do it in sendmail, but
i'm not sure how to do it in MS. and is this solution scalable,
should be need to do it for dozens or hundreds of addresses?


long version: 

one of the more irritating things about the 'spam problem' occurs when
a spammer uses your email address to sign a spam run. historically,
though, this has largely been a transient issue -- life is bad for a
few days, then the problem goes away. in the last few months, however,
this has -- sometimes -- changed: the Bad Guy never stops using
your address, so the bounces never stop.

there are a pile of possible ways to proceed; none of them really
perfect. one way is to:
  - change mailing list subscriptions, tell real people, etc etc etc.
  - change the lucky user's email address (in most cases,
    the spammer is using one of the mailEquivalentAddresses, so this
    is _comparatively_ painless)
  - refuse all mail to the old address at the gateway or MTA.
    unfortunately for us, our gateway doesn't have the ability
    to create a custom per-address error message, so by default
    it has to be at the MTA.

the third step needs to have a custom error message so if it should
happen to be legitimate mail the sender will (hopefully) get an SMTP
error that's useful. we've done this with sendmail for many years
via the access database, but (a) we haven't tackled it with MS yet and
(b) we don't yet have a test environment to tinker with. so what would
the recommended way be to do this? our sendmail access database has 
grown to several thousand for one reason or other, so i'd suspect
we want something that scales at least this well.

thanks in advance.

rp

rick pim                                           
rick-POYOzcKcYG0txLPZ/1ia6w@xxxxxxxxxxxxxxxx
information technology services                          (613) 533-2242
queen's university, kingston   
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