Kudos to the the mail team for a smooth upgrade (at least it looks
smooth from here)!

I'm looking forward to using the new features.

On the web client, the help pages have been updated and say there should
be a "Turn on SPAM checking" option. I'm not seeing that, should I just
be patient and it will pop up later?  Or is it these new bifocals?

I've never used SpamAssassin, but I thought it would score messages
numerically. The documentation only mentions adding SPAM to the subject
line. Maybe the header tag is an option not turned on here?

And on the virus scanning: I sent myself a Swen virus (detected by SAV)
using Mozilla from a account. It went thru undetected.
Speculation on why it wasn't detected?  (free software, ...)