Outlook Object Model is COM based, which means it can only be used from IE.
Even then, your script must come from a trusted site to be able to create local COM objects using new ActiveXObject()
.
Updated: try JS code like the following (off the top of my head, I am not a Java programmer).
Note that in general you cannot concatenate two HTML strings and produce a valid HTML string. You need to merge the two (look for the position of the "", insert your new HTML at that position).
var olApp = new ActiveAxObject("Outlook.Application");
var olItem = olApp.CreateItem(0);
var olOldBody = olItem.HTMLBody;
olOldBody.Importance = 2;
olItem.To = "email@company.com";
olItem.Cc = "";
olItem.Bcc = "";
olItem.Subject = "My subject text";
olItem.HTMLBody = "<span style='font-family: Arial, Helvetica, sans-serif; font-size:11pt; color: #00457C;'>" +
"<strong>Title1:</strong>Line1<br />" +
"<strong>Title2:</strong>Line2<br />" +
"<strong>Title3:</strong>Line3<br /></span>" + olOldBody;
olItem.Display();