You must be a little more specific. For example: what do you mean by "nice look" exactly?
To loop through files use Directory.GetFiles:
foreach (string fileName in Directory.GetFiles(@"c:\\"))
{
}
To learn more about how email template engine works you can read this article:
https://www.limilabs.com/blog/email-template-engine
Here's the small sample:
Contact data = ...;
string html = Template
.FromFile("template.txt")
.DataFrom(data)
.Render();
If you want to send an email with attachments use MailBuilder's AddAttachment method:
https://www.limilabs.com/blog/send-email-with-attachment
MailBuilder builder = new MailBuilder();
builder.From.Add(new MailBox("alice@mail.com", "Alice"));
builder.To.Add(new MailBox("bob@mail.com", "Bob"));
builder.Subject = "Test";
builder.Text = "This is a plain text message.";
builder.AddAttachment(@"../image.jpg");