Several factors could make Zimbra an attractive target: It has an established customer base and independent brand name. And it is not reliant on traffic from the Yahoo home page for customers, so pulling it from the Yahoo fold wouldn’t make much of a difference.

Worth noting that a potential Zimbra sale reemphasizes how poor Yahoo’s acquisition track record has been. Earlier this year, Yahoo shut down Maven Networks, only a year-and-a-half after purchasing the video platform company for $160 million. Swisher says it’s unlikely that Yahoo will get close to what it paid for Zimbra in a sale.

We’ve reached out to Yahoo for comment and will update if we hear back. A Yahoo spokesman says the company does not comment on “rumors or speculation”—but adds that Zimbra is a “critical part” of Yahoo’s communications products.

As for the other Yahoo properties up for sale, Reuters is now reporting that Yahoo wants between $350 million and $500 million for Yahoo Small Business—a price that some have deemed to be too high.