Hi 

I use odoo 10.0 on a OVH VPS 1vcore with 4gig of ram.

When i try to send a new message to a contact an error message pop. This is the log:

Traceback (most recent call last):
  File "/odoo/odoo-server/odoo/http.py", line 640, in _handle_exception
    return super(JsonRequest, self)._handle_exception(exception)
  File "/odoo/odoo-server/odoo/http.py", line 677, in dispatch
    result = self._call_function(**self.params)
  File "/odoo/odoo-server/odoo/http.py", line 333, in _call_function
    return checked_call(self.db, *args, **kwargs)
  File "/odoo/odoo-server/odoo/service/model.py", line 101, in wrapper
    return f(dbname, *args, **kwargs)
  File "/odoo/odoo-server/odoo/http.py", line 326, in checked_call
    result = self.endpoint(*a, **kw)
  File "/odoo/odoo-server/odoo/http.py", line 935, in __call__
    return self.method(*args, **kw)
  File "/odoo/odoo-server/odoo/http.py", line 506, in response_wrap
    response = f(*args, **kw)
  File "/odoo/odoo-server/addons/web/controllers/main.py", line 885, in call_kw
    return self._call_kw(model, method, args, kwargs)
  File "/odoo/odoo-server/addons/web/controllers/main.py", line 877, in _call_kw
    return call_kw(request.env[model], method, args, kwargs)
  File "/odoo/odoo-server/odoo/api.py", line 689, in call_kw
    return call_kw_multi(method, model, args, kwargs)
  File "/odoo/odoo-server/odoo/api.py", line 680, in call_kw_multi
    result = method(recs, *args, **kwargs)
  File "/odoo/odoo-server/addons/mail/models/mail_thread.py", line 1882, in message_post
    new_message = MailMessage.create(values)
  File "/odoo/odoo-server/addons/mail/models/mail_message.py", line 731, in create
    user_signature=self.env.context.get('mail_notify_user_signature', True))
  File "/odoo/odoo-server/addons/mail/models/mail_message.py", line 808, in _notify
    partners._notify(self, force_send=force_send, send_after_commit=send_after_commit, user_signature=user_signature)
  File "/odoo/odoo-server/addons/mail/models/res_partner.py", line 161, in _notify
    ('notify_email', '!=', 'none')])._notify_by_email(message, force_send=force_send, send_after_commit=send_after_commit, user_signature=user_signature)
  File "/odoo/odoo-server/addons/mail/models/res_partner.py", line 206, in _notify_by_email
    new_emails, new_recipients_nbr = self._notify_send(fol_values['body'], fol_values['subject'], recipient_template_values['followers'], **base_mail_values)
KeyError: 'body'