Slack introduced a new feature on Wednesday that allows people to privately message members of other Slack groups.
The move has caused some backlash on social media after it was introduced by the company.
The new feature is called Connect DMs, with DM standing for "direct messaging".
"Employees at more than 74,000 organisations and counting can now securely direct message anyone – inside or outside their company," Slack said on March 24.
It is an expansion of Slack Connect, which the platform introduced a year ago, where administrators of a Slack can give outsiders access to certain channels.
This comes in handy when one company is collaborating with another company or organisatione.
Connect DMs takes that a step further and allows people to message users on another Slack directly.
Outside of email, Slack is one of the largest work communication platforms, with more than 12 million users globally.
It also has more than156,000 paying clients, its latest quarterly earnings report states.
The company also says that 74,000 organisations are using Connect DMs.
Salesforce bought the platform for $27.7 billion in December 2020.
Connect DMs expands Slack from a place where people can chat with co-workers or collaborators within a single, invite-only Slack to a place where users can message anyone.
The new feature has received criticism over possible harassment and privacy issues, as well as the growing footprint of Slack in the work-life balance.
Some users have raised concerns about how Connect DMs could enable harassment in and outside the workplace.
Slack administrators can opt out of the new feature.
Many Twitter users have called for the platform to introduce a block feature to deal with harassment problems.
While the feature is called direct messaging and users could believe they are engaging in a private chat, NBC News tech reporter Kevin Collier said that Slack was, first and foremost, a workplace platform.
Collier said Slack was not the best place for secure private messaging, as it did not encrypt messages and made them available to employers.
Beyond that, the platform has often been compared to email, with users constantly having to answer unread alerts or messages in several channels on their work Slack.
