title: Emails with Firebase extension Trigger Email go to spam
body: <p>I have a contact form configured on my webpage (made with Flutter web) to send emails automatically with Firebase extension Trigger Email. However, they go directly to the spam folder. I have been reading about the causes why emails go to spam and I don't know if I have any of those. I think authentication (as said <a href="https://stackoverflow.com/questions/371/how-do-you-make-sure-email-you-send-programmatically-is-not-automatically-marked">here</a>) should not be a problem since the FROM email and the account logged in are the same.</p>
  <p>This is the configuration of the extension:
  <a href="https://i.stack.imgur.com/Xm3Fi.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Xm3Fi.png" alt="enter image description here" /></a></p>
  <p>And this is an example of an email sent:
  <a href="https://i.stack.imgur.com/lvj5Y.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/lvj5Y.png" alt="enter image description here" /></a></p>
  <p>This is the code to add the document to the firebase collection:</p>
  <pre><code>Future&lt;void&gt; _submitForm() async {
      final isValid = _key.currentState?.validate();
  
      if (isValid != null &amp;&amp; isValid) {
        _key.currentState?.save();
        String message;
  
        try {
          final collection = FirebaseFirestore.instance.collection(&quot;mail&quot;);
          await collection.doc().set({
            &quot;timestamp&quot;: FieldValue.serverTimestamp(),
            &quot;to&quot;: [&quot;Name LastName &lt;name.lastname@domain.com&gt;&quot;],
            &quot;message&quot;: {
              &quot;subject&quot;: _subject,
              &quot;text&quot;: &quot;Name: ${_name}\nEmail: ${_email}&quot;
                  &quot;\nPhone: ${_phone}\n\n${_message}&quot;
            }
          });
  
          _key.currentState?.reset();
  
          message = &quot;Your message has been sent successfully. We will get in &quot;
              &quot;contact with you.&quot;;
        } catch (_) {
          message = &quot;Your message could not be sent. Please try again later.&quot;;
        }
  
        ScaffoldMessenger.of(context)
            .showSnackBar(SnackBar(content: Text(message)));
      }
    }
  </code></pre>
  <p>Any idea how could I fix this?
  Thanks in advance.</p>