Is there any software that would be able to extract email addresses and put them into an Excel spreadsheet?

Yes, but the software would depend on where/how the email addresses are currently stored.

You can grep through the emails using the following regular expression to match email addresses:
m/^[a-zA-Z0–9._%]+@[a-zA-Z0–9.+\.[a-zA-Z]{2,4}/

It would take less than an hour to write and run Perl or Python script that scrubs through the emails to extra email addresses. How are the emails currently stored?

thanks! The emails are all just saved in his excite.com email. I suppose he could export those? Incidentally, the problem is that all of the emails were forwarded to him by the magazine’s assistant. So all 1500 emails are from the same address. The actual addresses we need are not in the “from:” part of the email, but are in the body of the email when you scroll down and see what was forwarded. I suppose the script coudl just scan for @ signs and do it that way?

Yeah, he would need to export them, preferably to plain text files that include the headers.

I’m not familiar with Excite email, but I’d guess that it’s possible. If not, you could always forward the messages to another email account that allows exporting.