My Openerp server is performing well, but when try to send an email it gives me this messages in the logs

I tried to add it to a local host sendmail instance and to different other mailservers, but it stays giving me this errors and not sending any mails

2013-07-15 13:13:59,736 1392 ERROR Efterom openerp.addons.base.ir.ir_mail_server: Mail versturen via SMTP server 'localhost"mislukt. AttributeError: SMTP instance has no attribute 'sendmail' Traceback (most recent call last): File "/usr/lib/pymodules/python2.7/openerp/addons/base/ir/ir_mail_server.py", line 461, in send_email smtp.sendmail(smtp_from, smtp_to_list, message.as_string()) AttributeError: SMTP instance has no attribute 'sendmail' 2013-07-15 13:13:59,737 1392 ERROR Efterom openerp.addons.mail.mail_mail: failed sending mail.mail 249 Traceback (most recent call last): File "/usr/lib/pymodules/python2.7/openerp/addons/mail/mail_mail.py", line 307, in send mail_server_id=mail.mail_server_id.id, context=context) File "/usr/lib/pymodules/python2.7/openerp/addons/base/ir/ir_mail_server.py", line 474, in send_email raise MailDeliveryException(_("Mail delivery failed"), msg) MailDeliveryException: (u'Mail afleveren mislukt', u'Mail versturen via SMTP server \'localhost"mislukt.\nAttributeError: SMTP instance has no attribute \'sendmail\'')

Anyone an idea?