They might be able to set their return address by configuring their
mail client.  I know you can do this with Pine:
 
# user-domain specifies the domain part of your return address on outgoing
# email and is also used as the default domain for email composed to a
# local user.  If unset, Unix Pine will obtain the domain from the system.
user-domain=
 
Of course, this depends on what client they're using.  If it's Eudora
or some such, I don't have the answer.  :)
 
Nathan
 
On Thu, 31 Aug 1995 10:17:51 EST Bob Kosovsky said:
>Now that I've engaged the option to send non-subsciber posts to me, a
>new problem has arisen.
>
>There is at least one internet provider, MCS.COM in Chicago, which switches
>nodes, apparently at whim.  Users logging into the system don't know
>whether they will be [log in to unmask]  or [log in to unmask] (they have
>about 5 of these, all named after planets).
>
>Is there any way around this, short of subscribing all manifestations of
>a particular user?  I don't suppose one could use:  User@*mcs.com  :)
>
>Thanks.
>Bob Kosovsky
>Student, PhD Program in Music                   Librarian
>Graduate Center                                 Music Division
>City University of New York                     The New York Public Library
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