Is all OK at waitrose.com?

[#1]

My wife uses waitrose.com for her email and, unusually, has received no incoming emails for about 48 hours. I sent her a test message that has not arrived, so things are looking a bit odd. I ask here if there is any known problem because I believe that PN now runs that service.
This has happened before. No emails for a day or so, then suddenly they all come.
Any ideas?
- Keith

[#2]

Problem solved!  It appears that my wife's email account on waitrose.com is allocated 50MB of storage there. We have it set up to delete messages that have been read after 30 days. Normally this works well. During the last few days, however, a number of jokey messages, including video clips, have been recieved from friends. Several of these messages have occupied around 10MB each.
It would appear that waitrose.com refuses to accept any new emails when there is no space to store them. Fair enough. It would also appear that the senders' ISPs keep retrying rather than issuing an error message to the sender because now that I have deleted several very large emails from the waitrose account some delayed messages are beginning to appear.
So, it all begins to make sense. If anyone else has a similar problem, this experience might be of help to them.
Season's greetings.