alias coverMicrosoft has enabled the use of aliases its widely-used Hotmail email service. The new feature enables Hotmail users to add temporary email addresses in situations when they do not wish to use their personal, or every-day email address.

According to Windows Live director of product management Dharmesh Mehta, the move is really about pushing Microsoft’s email beyond the competition.

And when he says “competition”, he means Google.

Aliases are a nifty way of routing one-time email correspondence (such as when shopping online) to one’s inbox without exposing the actual email address to possible spammers. Hotmail and other email services have so far incorporated the use of a special character in an address that will route the incoming messages accordingly.

Gmail, for instance, allows the use of the ‘+’ sign, like “johndoe+cardeals@gmail.com” which will direct all messages to the actual email address, maybe flagged as spam, starred for later, or routed to a specific folder. However, according to Mehta, Hotmail aliases are integrated into the service–meaning it’s easy to manage–and, more importantly, it can be easy to figure out a person’s actual email address from the ‘+ sign’ construction. For now, a Hotmail user can have five aliases, but the number will grow to fifteen later.

The new feature may be very convenient for heavy-duty email users, but it doesn’t seem too likely to win over new email users just by itself. Microsoft is in the process of revamping its service and has been adding new features and technology, such as sandboxing and additional security technology. All of these are intended to keep Hotmail head and shoulders above the rest, says Mehta.

“For us, [the competition is] really versus GMail. So how do we start to beat Gmail in a couple of different key scenarios certain customers are just going to like more?” Mehta asks in a CNET interview.

Microsoft’s Hotmail is currently the world’s most popular web-based email service with around 360 million users. Yahoo Mail is second with roughly 280 million, and Google’s Gmail–the youngest by far–is at third place with 190 million. But Google is the one to look out for, especially now that Google’s Android operating system is gaining popularity and driving mobile users to sign up for Google’s integrated services, such as Gmail.