I'm creating email to custom object records via the InboundEmailHandler.  (sorry if my verbage is wrong on that).

What I have working is the email to custom object, as well as the attachments to the record, but having issues creating a new EmailMessage that is associated with the custom object record.

I have all the fields figured out minus the toAddress since it's inserting via a list to string.  I'm not sure how to convert that to a list.  Any help would be appreciated.  Here is the code:

global class CreateTradeSupport implements Messaging.InboundEmailHandler {
    
    global Messaging.InboundEmailResult handleInboundEmail(Messaging.InboundEmail email, Messaging.InboundEnvelope env){
        
        Messaging.InboundEmailResult result = new Messaging.InboundEmailResult();
        
        String myPlainText= '';
        Contact c;
        myPlainText = email.plainTextBody;
        
        try{
            if([SELECT count() from Contact where email =:email.fromAddress] == 0){
                c = new Contact();
                c.LastName = email.fromName;
                c.Email = email.fromAddress;
                insert c; 
            }
            else{
                c = [SELECT Id from Contact Where email =:email.fromAddress LIMIT 1];
            }
            
            Trade_Support__c ts = new Trade_Support__c();
            ts.Description__c = myPlainText;
            ts.Status__c = 'New';
            ts.Subject__c = email.subject;
            ts.web_email__c = email.fromAddress;
            ts.contact__c = c.Id;
            insert ts;
            
            EmailMessage mail = new EmailMessage();
            mail.Subject = email.subject;
            mail.FromAddress = email.fromAddress;
            mail.HtmlBody = email.htmlBody;
            mail.TextBody = myPlainText;
            mail.FromName = email.fromName;
            mail.RelatedToId = ts.Id;
            
//This is where I'm having issues
            mail.toAddress = email.toAddresses;
            mail.CcAddress = email.ccAddresses;
            
            mail.Status = 'Read';
            insert mail;
            
            // Save attachments, if any
                List<Attachment> attachments = new List<Attachment>();
                if(email.textAttachments != null)
                {
                    for (Messaging.Inboundemail.TextAttachment tAttachment : email.textAttachments) {
                        Attachment attachment = new Attachment();
                        attachment.Name = tAttachment.fileName;
                        attachment.Body = Blob.valueOf(tAttachment.body);
                        attachment.ParentId = ts.Id;
                        attachments.add(attachment);
                    }
                }
                if(email.binaryAttachments != null)
                {
                    for (Messaging.Inboundemail.BinaryAttachment bAttachment : email.binaryAttachments) {
                        Attachment attachment = new Attachment();

                        attachment.Name = bAttachment.fileName;
                        attachment.Body = bAttachment.body;
                        attachment.ParentId = ts.Id;
                        attachments.add(attachment);
                    }
                }
                if(attachments.size() > 0)
                {
                    insert attachments;
                }
            

        }
        catch (QueryException e) {
            System.debug('Query Issue:  ' + e);
        }
        
        result.success = true;
        
        return result;
        
        
    }

}