phpmailer AddStringAttachment doesn't work

Hello there,

We encounter an issue with FluentSMTP, our plugin attaches an attachment to the mails with $phpmailer->AddStringAttachment however this logic doesn't work with FluentSMTP, so the wp_mail throws an exception due to file path issue.

When I suppress wp_mail override on

fluent-smtp/fluent-smtp.php

Lines 39 to 43 in b4cf18a

    
           if (!function_exists('wp_mail')) : 
        
               function wp_mail($to, $subject, $message, $headers = '', $attachments = array()) 
        
               { 
        
                   return fluentMailSend($to, $subject, $message, $headers, $attachments); 
        
               }

it works.

Could you please check the issue?
Thanks

	if (!function_exists('wp_mail')) :
	function wp_mail($to, $subject, $message, $headers = '', $attachments = array())
	{
	return fluentMailSend($to, $subject, $message, $headers, $attachments);
	}