'Override the method giving the evaluation context but also the
context used in all subsequent calls. Add the mail_notify_force_send
key set to False in the context. This way all notification emails linked
to the currently executed action will be set in the queue instead of
sent directly. This will avoid possible break in transactions.'

@api.model
def _get_eval_context(self, action=None):

    eval_context = super(ServerActions, self)._get_eval_context(action=action)
    ctx = dict(eval_context.get('context', {}))
    ctx['mail_notify_force_send'] = False
    eval_context['context'] = ctx
    return eval_context
