I've just noticed that this server has 30 or 40 messages in the mail queue with attachments such as "wicked_scr.scr" or "document_9446.pif" - I wonder if there has been another bout of email viruses going around that have slowed things down a bit.
I noticed some slowness this evening, especially trying to get to beyond3d.com. But then I saw that it might have been down for a short while anyway, so perhaps the other instances were coincidences too.