I have been getting this error report daily for about 20 days now.
Every day, it shows the error count as "1" for both of these people.
The third entry, [log in to unmask] is new to today's report.

I've done searches through the subscriber lists for "Walker," "Alice,"
"Lee," "astound.net" and "feliks."  Also, Richard Lee's email address
is not always the same in the error reports.  Sometimes it is as
below, other times it's "[log in to unmask]"

Since I can't find these subscribers on my list
([log in to unmask]) and everyday seems like their "first" error,
can someone give me some advice on what I can do?

Thanks,

Cindi

*********

The following 3 subscribers are currently being monitored:

Err First Last  Address
--- ----- ----- -------
  1 11/11 11/11 "Alice A. Walker" <[log in to unmask]>
                Last error: 5.1.1 550 Invalid recipient:
                            <[log in to unmask]>

  1 11/16 11/16 "Richard K. Lee" <[log in to unmask]>
                Last error: 5.1.1 550 5.1.1 <[log in to unmask]>... User
                            unknown

  1 11/25 11/25 "Alice A. Walker" <[log in to unmask]>
                Last error: 5.0.0 X-Postfix; service unavailable

Err=   Number of delivery errors received thus far
First= Date first delivery error was received (mm/dd) Last=  Date of
most current delivery error (mm/dd)

Subscribers will be automatically deleted from the list when delivery
errors have been  reported for a period  of 15 days  or more, or when
100 delivery errors have  been received,  whichever occurs  first.
Monitoring  will cease after 16 days without any reported error.

Note: manually deleted subscribers may remain on the monitoring report
under an alias address. Such entries will expire eventually; you do
not need to do anything about them.