diff --git a/addons/project/models/project.py b/addons/project/models/project.py
index a68e98986c0..1fc6131ee0c 100644
--- a/addons/project/models/project.py
+++ b/addons/project/models/project.py
@@ -1172,7 +1172,7 @@ class Task(models.Model):
     @api.depends('partner_id.email', 'parent_id.email_from')
     def _compute_email_from(self):
         for task in self:
-            task.email_from = task.partner_id.email or task.email_from or task.parent_id.email_from
+            task.email_from = task.partner_id.email or ((task.partner_id or task.parent_id) and task.email_from) or task.parent_id.email_from
 
     @api.depends('parent_id.project_id.subtask_project_id')
     def _compute_project_id(self):