sendmail sends multiple copies of same email, some in to: field never reach destination

Hello,

I am using sendmail-8.12.8-9.90 on a redhat 9.0 system.

The problem I have come up against is this:

A user sent an email to 28 people.  Just a basic email with text in it.  Some of the recipients have addresses that end in .mil.  We have recently discovered that the Department of Defense decided to block mail from our domain to several of their departments, namely, one of our most important clients, and have had several mails either bounce back, or they get through after some number of tries.

With THIS email, however, many people that don't have .mil addresses have received the same email multiple times, one as many as SIXTY times, and several other addresses many times as well, though not nearly as much as the poor sucker who got 60+.

I can tell from the maillogs that sendmail is still trying to send the mail out to the .mil addresses 8 days later, and, they get tried every 30 minutes, but the connection gets timed out, because the b*st*rds blocked mx and web traffic.  The people who got multiple copies are still receiving them as well to this day.

How can I prevent people in a multi-to email from receiving multiple copies when one or more addresses time out, and, how do I stop the darned program from trying past a certain number of days?  Has anyone seen this crazy problem?

Thanks,

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