Hi,
I recently received this message when sending an email (MS Outlook):
Category: Email Errors
Date & Time,Risk,Activity,Status,Recommended Action
2012-01-31 09:14:29,High,421 Resources temporarily unavailable - Please try again later ,Error,No Action Required
I discovered that the email had not been sent although it showed as sent in Outlook.
What does this error mean please?
edit: I recently installed Norton Utilities as part of my new subscription; not sure if that is relevant.
It just happened again, twice, for an email.
Some help would be appreciated
Hi baldeagleuk:
Please read this entire thread for your answer... no worries... It happens. 
http://community.norton.com/t5/Norton-Internet-Security-Norton/421-Resources-Temporarily-Unavailable/m-p/642957/highlight/true#M191729
Hope that this answers your questions. If not, please post back.
Regards,
Atomic_Blast :)
Thank you for the quick response. I have never seen the message before and I have used NIS for several years. I DO get error messages from the ISP (BT) when there is a problem with logon or timeout.
The annoying thing with NIS doing it is that the email has to be re-sent.
Anyway, I will keep my eye on it.
Hi baldeagleuk:
These 421 Resource messages should be very transient in nature.
If you are having continued problem, definitely contact your Mailhost and/or ISP.
Remember that NIS is just reporting the error and that it is not a NIS issue. 
Take care!
Atomic_Blast :)