Looks like a simple "finger check" to me: you appeared to have
inserted a period between 'tam' and '2000'.
 
 
>>    ----- Transcript of session follows -----
>> 550 tam.2000.tamu.edu.forgn... 550 Host unknown
>> 554 <@jazz.epas.utoronto.ca:[log in to unmask]>... 550 Host unknown (
                                       !!!!!!!!
>+ Authoritative answer from name server)
>>
>>    ----- Unsent message follows -----
>> From: "P. Divirgilio" <[log in to unmask]>
>> Subject: Re: Your request to sign off the COMPUMED list (fwd)
>> To: [log in to unmask]
               !!!!!!!!
>> Date: Mon, 24 Oct 1994 13:33:14 -0400 (EDT)
>> > From: "Fidel Davila"  <[log in to unmask]>
>> > I subscribe to COMPUMED under "[log in to unmask]". My address has
>+ since
>> > been changed locally to "[log in to unmask]".
>[log in to unmask]