A number of folk sending us emails are receiving delay notifictions - ie:
From: Mail Delivery System [mailto:email@example.com] Sent: 19 March 2009 11:33 To: firstname.lastname@example.org Subject: Warning: message delayed 25 hours This message was created automatically by mail delivery software. A message that you sent has not yet been delivered to one or more of its recipients after 25 hours. The message has not yet been delivered to the following addresses: <email@example.com> SMTP error from remote server after RCPT command: host mx-ironport.core.plus.net[126.96.36.199]: 452 Too many recipients received this hour No action is required on your part. Delivery attempts will continue for some time, and this warning may be repeated at intervals if the message remains undelivered. Eventually the mail delivery software will give up, and when that happens, the message will be returned to you.