Principals say teachers are being swamped by an increasing number of emails from demanding parents.
WA Primary Principals Association president Stephen Breen said the overuse of email had become a problem in some schools in the past two years, with more parents resorting to emails to discuss complex issues or to ask teachers to resolve classroom conflicts.
Mr Breen said many parents also expected instant responses, without allowing for teachers being in class or on playground duty.
"It's hit the crescendo now where many parents feel more comfortable sending off an email than getting in the car and driving to the school and having a chat," he said.
"Unfortunately a lot of schools have been forced into saying they can't accept emails for various things."
Mr Breen said emails should be used only for information purposes, not as a conflict management tool.
The Education Department said it was up to individual public schools to set the guidelines.
Catholic Secondary Principals Association president Peter Bothe said more schools were developing email correspondence protocols because of increased pressure on teachers and growing expectations from parents.
Mr Bothe, who is also principal of Sacred Heart College, said he recently used his school newsletter to tell parents they could not reasonably expect a response to an email within a day.
He said 48 hours was a fair turnaround time for teachers who were busy teaching, on yard duty, marking or supervising after-school activities.
"I felt as though some of my young teachers were feeling very pressured and I had some of my parents complaining that they hadn't heard back from a teacher within a day," he said.