For a brief period (two hours or less) earlier today (Tuesday, 26 November),
the outbound electronic mail process on one of the central systems
(Rose.MUOhio.Edu, a/k/a MailFwd.MUOhio.Edu) was misconfigured *not* to use Mail
Exchanger (MX) records in delivering outbound e-mail.
 
MX records help resolve host.domain name aliases to the names of actual host
systems capable of receiving e-mail.
 
For the period of time that Rose / MailFwd was misconfigured, outbound e-mail
to several MX'd host.domains (notably including America Online, aol.com) was
returned to sender with an error message reading "550 Host unknown."
 
The problem was quickly recognized and corrected by MCIS Technical Support.
Anyone whose outbound e-mail was returned to them with a "550 Host unknown"
error message, should simply re-send their mail messages, which should now
deliver properly.
 
MCIS regrets any inconvenience this problem caused.
 
--
 
          Miami University
 
          John B Harlan
          Campus Wide Information Systems (CWIS) Coordinator
 
          Miami Computing & Information Services (MCIS) Client Services
          137 Hoyt Hall
          Oxford, Ohio 45056-1618
          (513) 529-5330 voice  (513) 529-5058 fax
          [log in to unmask]
          http://miavx1.muohio.edu/~harlanjb/