Can't receive emails sent from a Codeception test - php

Question

I have a local Wordpress website that sends emails successfully, however if I try to send an email from a Codeception integration test, I do not receive any emails. (By the way, I don't think the problem has to do with Wordpress, which is why I'm posting here rather than Wordpress Stack Exchange).
I've configured Wordpress like this:
add_action( "phpmailer_init", array( $this, "configure_mailer" ) );
function configure_mailer( $mailer ) {
$mailer->isSMTP();
$mailer->Host = "smtp.gmail.com";
$mailer->SMTPAuth = true;
$mailer->Username = "myemail#gmail.com";
$mailer->Password = "mypassword";
$mailer->SMTPSecure = "tls";
$mailer->Port = 587;
$mailer->IsHTML( true );
}
Now if I try to send an email with wp_mail (which internally uses a PHPMailer instance configured as above) from my Wordpress code, eg. via an API request, I do receive the email:
// This is the custom API route that sends the email
register_rest_route( "mynamespace/v1", "/send-email", [
"methods" => \WP_REST_Server::CREATABLE,
"permission_callback" => "__return_true",
"callback" => function() {
$result = wp_mail( "myemail#example.com", "Test subject", "Test message", array( "From: MySite <myemail#example.com>");
return new \WP_REST_Response( $result );
}
]);
// This is the API request
POST https://example.com/wp-json/mynamespace/v1/send-email
The above request returns true because wp_mail returns true (as it does when an email is sent successfully), and I receive the email.
If I try to send the email from a Codeception integration test, the test succeeds because wp_mail still returns true, but I do not receive the email. (The \Codeception\TestCase\WPTestCase comes from wpbrowser, a package I use for testing Wordpress with Codeception).
class EmailTest extends \Codeception\TestCase\WPTestCase {
public function testSendsEmail() {
$result = wp_mail( "myemail#example.com", "Test subject", "Test message", array( "From: MySite <myemail#mysite.com>");
$this->assertTrue( $result );
}
}