odoo/addons/crm/res_config_view.xml

<openerp>
    <data>

        <record id="view_sales_config_crm" model="ir.ui.view">
            <field name="name">Sales Application</field>
            <field name="model">res.config</field>
            <field name="type">form</field>
            <field name="inherit_id" ref="base.res_config_view_base"/>
            <field name="arch" type="xml">
                <xpath expr="//form/group[@name='emails']" position="inside">
                    <group col="4" colspan="2">
                        <separator string="Emails" colspan="4"/>
                        <field name="fetchmail_crm" />
                        <newline/>
                        <group col="4" colspan="2"
                            attrs="{'invisible': [('fetchmail_crm','=',False)]}">
                                <field name="server" attrs="{'required': [('fetchmail_crm','=',True)]}"/>
                                <field name="type" nolabel="1" on_change="onchange_server_type(type, is_ssl)" attrs="{'required': [('fetchmail_crm','=',True)]}"/>
                                <field name="port" attrs="{'required': [('fetchmail_crm','=',True)]}"/>
                                <field name="is_ssl" on_change="onchange_server_type(type, is_ssl)"/>
                                <newline/>
                                <field name="user" attrs="{'required': [('fetchmail_crm','=',True)]}"/>
                                <field name="password" password="True" attrs="{'required': [('fetchmail_crm','=',True)]}"/>
                        </group>
                    </group>
                </xpath>
                <xpath expr="//form/group[@name='synchronization']" position="inside">
                    <group colspan="2" col="2">
                       <field name="crm_caldav"/>
                    </group>
                </xpath>
            </field>
        </record>

    </data>
</openerp>