Hi Jennifer,
What kind of mass emails are you trying to send? I know several of the property management software systems have the ability to mass email prospects, but we've found that you're typically better served going with an email marketing service from outside the industry -- take a look at services like ExactTarget, MailChimp, or Constant Contact. You can send mass emails for offers like a featured floor plan or a special of the week, and you can also set up more customized messages that are personalized for each individual, based on where they're at in the buying process.
Depending on the system, you can also track prospect activities to see which emails they open, which ones they take action on, and even which pages they visit on your website ... and you can automatically adjust your messaging based on the actions taken. So you could do things like send a follow-up email after a prospect views a floor plan page on your website.
As far as prospect tracking, I think that Anyone Home has the best approach in the industry. Besides the other options you already know, you could check out Lead Tracking Solutions by Yardi. There are some great CRM systems outside the industry, too ... HubSpot's CRM is free, and there are lots of other solid options that integrate directly with the email services I mentioned above.
Good luck, and let us know what you end up going with!