I will emphatically state that this issue is not a temporary one and I have spent time with Verizon support who have kept on insisting to remote-into my PC and can't get past that point. I will NEVER allow that.
Over the years I have managed my parents email account and have over a dozen email filters (rules) such as...
If From Contains Viagra delete
I have been able to manipulate email filters (rules) for years, that is until now 
I wanted to add a new rule (filter) but I got the following...
So I choose "Yes" and the function proceeds...
The above will continue to show the circling arrows sprite rotating to the right of "Cleaning Filters..." until the webmail site eventually times-out from inactivity.
The "Cleaning Filters..." function NEVER completes.
Thus I am completely unable to; add, edit or delete filter rules.
I have tested this on Firefox v7 and IE8 on Windows XP as well as used Firefox v15.01 and IE9 on Windows Vista.
All with equal results. The "Cleaning Filters..." function NEVER completes.
That's two OS' and two different Browsers representing four different Browser versions.
The problem is Browser independent, OS independent and exists on the Webmail server and needs to be fixed on the webmail server.
I have told technical support there are two remedies.
1. Fix the problem on the server(s)
2. Reset the associated email account. This will delete all email filters (rules) and other personal settings but will allow the addition of new rules (without duplicates) and other settings can subsequently be manually re-entered as well.
