Volkswagen has agreed to stop its Blackberry servers sending emails to some of its employees when they are off-shift.
The carmaker confirmed it made the move earlier this year following complaints that staff's work and home lives were becoming blurred.
The restriction covers employees in Germany working under trade union negotiated contracts.
Campaigners warned that the move would not be suitable for all companies.
A spokesman for VW said: "We confirm that this agreement between VW and the company's work council exists", but would not comment further.
Under the arrangement servers stop routing emails 30 minutes after the end of employees' shifts, and then start again 30 minutes before they return to work.
The staff can still use their devices to make calls and the rule does not apply to senior management.
"We wanted to take a preventative approach to tackling the issue," said Gunnar Killian, VW's works council spokesman.
"At Volkswagen flexitime is between 0730-1745, with our new arrangement workers can only receive emails between 0700 and 1815."
The move follows criticism of internal emails by Thierry Breton, chief executive of the French information technology services giant, Atos. He saidworkers at his firm were wasting hours of their lives on internal messagesboth at home and at work. He has taken the more radical step of banning internal email altogether from 2014.
Last month the maker of Persil washing powder, Henkel, also declared an email "amnesty" for its workers between Christmas and New Year saying messages should only be sent out as an emergency measure.
Industry watchers say the moves reflect growing awareness of a problem.
"It's bad for the individual worker's performance being online and available 24-7. You do need downtime, you do need periods in which you can actually reflect on something without needing instantaneously to give a reaction," said Will Hutton, chair of the Big Innovation Centre at The Work Foundation.
"Secondly it has a poor impact on an individual's well-being. I think that one has to patrol quite carefully the borderline between work and non-work.
"So I can see why some firms are taking this action, the problem is that a universal response is impossible... but certainly we should have the capacity to be opted out of it rather than be opted in."
Union officials in the UK have also cautioned other firms against repeating Volkswagen's move without consultation.
"The issue of employees using Blackberrys, computers and other devices out of working time is a growing one that needs to be addressed as it can be a source of stress," Trades Union Congress (TUC) secretary general Brendan Barber told the BBC.
"However other organisations will need different solutions and what works in VW may not work elsewhere.
"By working in partnership with their union, Volkswagen's policy will have the support of all their employees. Where employers simply introduce policies on their own, however well-meaning they may be, they are unlikely to be successful."