Hi,

In Odoo email templates, your code didn’t work as expected because message_follower_ids points to mail.followers, not partners directly. The correct way is to map them to their partners.

Try the following code:

<p><strong>Sent To:</strong><br/>

Partner: <t t-esc="object.partner_id.name"/> &lt;<t t-esc="object.partner_id.email or ''"/>&gt;

</p>

<p><strong>Followers:</strong><br/>

<t t-foreach="object.message_follower_ids.mapped('partner_id')" t-as="follower">

    <t t-esc="follower.name"/> &lt;<t t-esc="follower.email or ''"/>&gt;<br/>

</t>

</p>

Or

<p><strong>Partner:</strong> <t t-esc="object.partner_id.name"/> &lt;<t t-esc="object.partner_id.email or ''"/>&gt;</p>

<p><strong>Followers:</strong><br/>

<t t-foreach="object.message_follower_ids.mapped('partner_id')" t-as="follower">

    <t t-esc="follower.name"/> &lt;<t t-esc="follower.email or ''"/>&gt;<br/>

</t>

</p>

Hope it helps