I currently have an Excel spreadsheet containing the names of prospective/existing clients (organizations), their "Contact Us" web page URL, an email address of the main contact, and the contact's name.
Periodically, this information may change: the most important is the email address, of course.
I'd like to find a way to automate some or all of the following processes:
1. Check whether the URL works (i.e., no 404 error or redirection script)
2. Check whether the email address that we have on record has changed (or been removed)
3. Check whether the contact name has changed (or been removed)
If anything has indeed changed, the new data must be recorded and updated.
OTHER NOTES: The solution need not necessarily be hosted on a web server; it could also be run locally from a decent desktop computer.
There is also no need to keep this system in Excel exclusively. The spreadsheet currently keeps track of Organization Name, URL, Contact Email Address, and Contact Name.
There is also no dire need to bypass anti-crawler/spider systems. Historically, these sites have been relatively simple and unsophisticated. For example, email addresses are rarely posted as an image and are almost always intact in the plain source code.