usually they are safe or should you once a new dat is discovered to run a new scan?
If Mcafee find the artemis is because is identified and properly cleaned or if message is deleted do you have to do something else?
There's any other recommendation?
Artemis is the name for the Active Protection component of VirusScan. When something is detected 'heuristically' and VirusScan isn't sure about it it consults an online database and if it still think it could be dangerous it quarantines it and labels it Artemis!xxxxxxxx where xxxx can be just about anything depending on where it indexes it.
It is explained here: http://community.mcafee.com/message/98519#98519
If you think it is an incorrect analysis then read here: http://community.mcafee.com/message/6645#6645 where you can see how to disable it if you wish to, not recommended, however.