odoo16/addons/mass_mailing/wizard/mailing_contact_import_views.xml

<?xml version="1.0"?>
<odoo>
    <record id="mailing_contact_import_view_form" model="ir.ui.view">
        <field name="name">mailing.contact.import.view.form</field>
        <field name="model">mailing.contact.import</field>
        <field name="arch" type="xml">
            <form string="Import Mailing Contacts">
                <group>
                    <field name="mailing_list_ids" string="Import contacts in"
                        widget="many2many_tags" placeholder="Select mailing lists"
                        options="{'no_create': True}"/>
                </group>
                <p>
                    Write or paste email addresses in the field below.
                    Each line will be imported as a mailing list contact.
                </p>
                <label for="contact_list" class="mb-2">Contact List</label>
                <field name="contact_list"
                    nolabel="1" default_focus="1"
                    placeholder='"Damien Roberts" &lt;d.roberts@example.com&gt;&#10;"Rick Sanchez" &lt;rick_sanchez@example.com&gt;&#10;victor_hugo@example.com'/>
                <p class="text-muted mb-0">
                    Want to import country, company name and more?
                    <button type="object" name="action_open_base_import"
                        class="fw-normal px-0 btn btn-link">
                        Upload a file
                    </button>
                </p>
                <footer>
                    <button string="Import" type="object" name="action_import"
                        class="btn-primary" data-hotkey="i"/>
                    <button string="Discard" class="btn-secondary"
                        special="cancel" data-hotkey="z"/>
                </footer>
            </form>
        </field>
    </record>

    <record id="mailing_contact_import_action" model="ir.actions.act_window">
        <field name="name">Import Mailing Contacts</field>
        <field name="res_model">mailing.contact.import</field>
        <field name="view_mode">form</field>
        <field name="target">new</field>
    </record>
</odoo>