Windows Live Mail suddenly extremely sluggish send and receive, sometimes fails

For some reason Windows Live Mail has stopped functioning properly for send and receive.  Outgoing messages remain in the Outbox for 10 minutes or more, and sometimes don't send at all.  On send/receive, the green bar showing progress gets hung-up toward the end and just stays that way.  Eventually the messages will download, but it can take forever.  I'm running Windows 7 on a Dell XPS.

Can anyone help?  I've run a repair on Windows Live Mail, done virus scan, etc.

Thanks,
k.