All of our 5 NW6.5SP7 give this error when trying to configure the NRM "Mail Notification Configuration" for the "Primary Mail Server Name".

File resolv.cfg (last line empty) looks nice :

File hosts (last line empty) looks nice : loopback lb localhost HEC11

ping / nwping / nslookup to the smtp server name "" works fine.

Display SMTP Mail Screen gives the following error when "Send config report" :

Connecting to Mail Server (
Sending from: (<HEC11@[]>).
Error from MAIL FROM command
Mail connection failed, err = 501.

The only weird thing is when :
I ping "", it gives an error.
I ping "smtp", it's ok.

Is there some wrong settings in TCP/IP / SMTP / NRM / iManager ?

Thanks for an idea ...