After more than five years officially in testing mode, Gmail is finally graduating from "beta."

Google says its email service and three other applications in the Google Apps suite for businesses are now finished products in name as well as function.

But that doesn't mean Google is finished improving upon them. Nor were the extra features announced Tuesday cause for dropping the label.

In fact, getting rid of beta doesn't mean a whole lot.

So why drop it?

Google concedes the move is aimed more at wooing business customers than marking any real developmental milestone.

The premier edition Apps suite sells for US$50 per user to business customers, who get added features including offline access and 24/7 customer support. The "beta" label was scaring businesses off.

"Many of the companies that have looked in depth at the apps have seen that they are feature complete," Rajen Sheth, a Google senior product manager, said in an interview.

"But there is a kind of perception thing, and in many cases that stops companies in their tracks from even looking at it."

Google Calendar, Google Docs and Google Talk are now out of beta mode. Google Sites and Google Video have already dropped the label.

Other Google applications not included in Apps suite - such as Google Scholars - will still carry the tag.

Nostalgic Gmail users will even have the option to restore the "beta" tag on their own screens.

The Mountain View, California, company announced two new Gmail features it will roll out to premier business customers over the next few weeks. One allows administrative assistants to send email on others' behalf, while the other lets companies automatically purge old emails after a certain period of time.

Google also said it will begin storing business-grade emails at two data centres simultaneously, reducing the likelihood of downtime.

The company says it has about 1.75 billion businesses using Google Apps, though it will not say how many are paying customers.