Thus far my initial findings as to the reason for many of the recent e-mails failing to reach us since 9-16-07 - were likely due to a resident spam-filter function emanating from our web-based e-mail server.
I have contacted our Web Developer/Host to look into this matter further to make certain that all of the settings and filters are properly configured so this cannot happen again.
The filter in-effect, dumped an indiscriminate number of e-mails into a bulk-folder -deeming it spam, thus failing to forward the e-mails to our primary MS-Outlook account to which we administer daily.
Due to the fact that we were receiving many other e-mails and confirmations as normal, it took us much longer than usual to realize that a portion of our mail was not getting through.
At this time, I believe we have "caught-up," and responded to each of the back-logged e-mails.
In addition, we have installed a redundant-direct notification module on our desktops. This will provide us with a back-up alert system beyond the MS-outlook platform in notifying us when new mail has arrived on our web-server account.