Google's popular email service has a new milestone to its credit. Gmail now accounts for a billion monthly active users.

On Monday, during the first-ever earnings call for Alphabet, Google's parent company, Google's CEO Sundar Pichai spilled the beans that the email service now accounts for 1 billion active monthly users.

The landmark figure means that Gmail brought the seventh feather in Google's cap. It has now joined other products in the 1 billion user club, such as YouTube, Chrome, Android, Play, Search and Maps.

Google shared the landmark achievement and expressed its gratitude toward users through Twitter.

Thanks a billion for helping us make Gmail better and better!https://t.co/Rd82YqwGjl

— Gmail (@gmail) February 1, 2016

Interestingly, the Android app for Gmail hit the magic figure of a billion installs in May 2014, two years after Gmail became the most sought after email service.

Gmail's growth has been on an upward swing steadily and in May 2015, the company revealed that it had already touched the 900 million active users mark. This announcement was accompanied by the introduction of the Inbox app.

Gmail beta was launched in 2004 and ceased to be called beta in 2009. In the last decade, the email service has become synonymous with users and businesses alike.

Since the onset of mobile apps for Android and iOS, the adoption of Gmail on smartphones remains phenomenal. Some notable enhancement includes improvement in the filtering process, and how Gmail can effectively sort emails into marketing, promotions, spam and personal.

The service also looks elegant thanks to its utilization of Material Design, which was announced together with the arrival of Android Lollipop in 2014.

In 2014, Google also launched a new feature - Inbox by Google, which was basically an email client that would make it simpler for users of the service to bypass bogus emails. The idea was to achieve "Inbox Zero" where a user could stay on top of any mail that was sent to them. The app would also enable users to dismiss emails swiftly through gestures.

In 2015, Google introduced its Smart Reply feature for Gmail users. This Inbox feature enables users to swiftly respond thanks to auto-generated suggested messages. The Google CEO disclosed that users of Inbox by Gmail generate 10 percent of their responses through Smart Reply.