Mails to this list - greylisted because allegedly Windows

[Andreas v. Heydwolff]

Hi again. How come that I get a message like the one below in the queue 
upon posting to this honorable list, although the sending machines are 
definitely *not Windows*? Just curious.

Andreas


-Queue ID- --Size-- ----Arrival Time---- -Sender/Recipient-------
00A82C0BF      8137 Wed Jan 31 20:50:50  address@hidden
(host mx20.gnu.org[199.232.41.8] said: 451-You seem to be a Windows 
machine. Our condolences. You're greylisted for 20 451 minutes. Come 
back later. (in reply to RCPT TO command)
)
                                         address@hidden