From the mailing list server administrators:
"I wanted to give advanced notice that on 3-21-15 there will be Data Center maintenance that will cause the LLVM mail list to be delayed.
There will be power changes done that require the power down of the Data Center. Email will be queued during that time.
The work is scheduled for 5am to 3pm CST on the Saturday of March 21, 2015. Again, email will be queued for delivery; we expect no loss just a delay."