odoo16/addons/mail/views/mail_gateway_allowed_views.xml

<?xml version="1.0" encoding="UTF-8"?>
<odoo>
    <record id="mail_gateway_allowed_view_tree" model="ir.ui.view">
        <field name="name">mail.gateway.allowed.view.tree</field>
        <field name="model">mail.gateway.allowed</field>
        <field name="arch" type="xml">
            <tree string="Mail Gateway Allowed" editable="top">
                <field name="email"/>
            </tree>
        </field>
    </record>

    <record id="mail_gateway_allowed_view_search" model="ir.ui.view">
        <field name="name">mail.gateway.allowed.view.search</field>
        <field name="model">mail.gateway.allowed</field>
        <field name="arch" type="xml">
            <search>
                <field name="email"/>
            </search>
        </field>
    </record>

    <record id="mail_gateway_allowed_action" model="ir.actions.act_window">
        <field name="name">Mail Gateway Allowed</field>
        <field name="res_model">mail.gateway.allowed</field>
        <field name="view_mode">tree</field>
    </record>
</odoo>