That's computer geek-speak for "your email won't work for a while."
Nearly all the main FRC computer systems are being updated. The FRC email you send or would receive during maintenance will be stored and delivered once the maintenance is complete, probably in a few days. Email should not be lost, just delayed. Meanwhile, you can communicate with your instructor and other students in your courses through the forums (discussion groups) in your course area.
Other course functions and the main FRC web site should work normally since both the FRC web site and Moodle are housed off campus. The maintenance will only impact campus computers and FRC email.
I'll let you know when the maintenance is completed, but I may not know the minute it is done. I'm not directly involved in the process.
Have a great weekend!
Mick