vieterp_mailbox/data/cron.xml

<?xml version="1.0" encoding="utf-8"?>
<openerp>
    <data noupdate="1">
        <record id="ir_cron_mail_gateway_action" model="ir.cron">
            <field name="name">Fetchmail Inbox Service</field>
            <field name="interval_number">1</field>
            <field name="interval_type">minutes</field>
            <field name="numbercall">-1</field>
            <field name="doall" eval="False"/>
            <field name="model">fetchmail.server.inbox</field>
            <field name="function">_fetch_mails</field>
            <field name="args">()</field>
            <field name="active" eval="True"/>
        </record>
    </data>
</openerp>