weird mail logs making me nervous

[Bud Rogers <budr@sirinet.net>]

I starting to see a lot of these in the logs.  Also I occasionally find 
return messages in the queue about failure to deliver one of those 
something.fsf@ emails.  I figure a spammer is messing with me, but I 
haven't figured out exactly what's going on.   Can anyone shed any 
light on this for me?

budr@twocups:~$ sudo grep local-part  /var/log/mail
Feb 10 08:50:08 twocups exim[28482]: 2001-02-10 08:50:08 
14RbLi-0007PN-00 ** m2emuhvr5h.fsf@twocups.sirinet.net: unknown 
local-part "m2emuhvr5h.fsf" in domain "twocups.sirinet.net"
Feb 10 14:55:09 twocups exim[10389]: 2001-02-10 14:55:09 
14Rh2y-0002hY-00 ** m2vhnskc82.fsf@twocups.sirinet.net: unknown 
local-part "m2vhnskc82.fsf" in domain "twocups.sirinet.net"
Feb 10 14:57:32 twocups exim[10398]: 2001-02-10 14:57:32 
14Rh55-0002hh-00 ** m2emuhvr5h.fsf@twocups.sirinet.net: unknown 
local-part "m2emuhvr5h.fsf" in domain "twocups.sirinet.net"
Feb 10 14:57:32 twocups exim[10398]: 2001-02-10 14:57:32 
14Rh55-0002hh-00 ** m2iujui0dq.fsf@twocups.sirinet.net: unknown 
local-part "m2iujui0dq.fsf" in domain "twocups.sirinet.net"
Feb 10 14:57:32 twocups exim[10398]: 2001-02-10 14:57:32 
14Rh55-0002hh-00 ** m2k94f9za3.fsf@twocups.sirinet.net: unknown 
local-part "m2k94f9za3.fsf" in domain "twocups.sirinet.net"
Feb 10 15:07:43 twocups exim[10449]: 2001-02-10 15:07:43 
14RhEq-0002iL-00 ** m290kr1rzy.fsf@twocups.sirinet.net: unknown 
local-part "m290kr1rzy.fsf" in domain "twocups.sirinet.net"
budr@twocups:~$

-- 
Bud Rogers <budr@sirinet.net>   http://www.sirinet.net/~budr/zamm.html
    All things in moderation.  And not too much moderation either.