'ir.attachment', 'mass_mailing_ir_attachments_rel',
'mass_mailing_id', 'attachment_id', 'Attachments'
),
+ 'keep_archives': fields.boolean('Keep Archives'),
'mass_mailing_campaign_id': fields.many2one(
'mail.mass_mailing.campaign', 'Mass Mailing Campaign',
ondelete='set null',