Premailer with Postal

gistfile1.cs

public class MailSender
{
  static MailSender()
  {
    var viewRenderer = new EmailViewRenderer(ViewEngines.Engines) {EmailViewDirectoryName = "UserMailer"};
    var emailParser = new EmailParser(viewRenderer);
    Email.CreateEmailService = ()=>new EmailService(viewRenderer, new PremailerEmailParser(emailParser), ()=>new SmtpClient());            
  }
  
  public void SendEmail()
  {
    // do all your normal email stuff
  }
  
  private class PremailerEmailParser : IEmailParser
  {
      private readonly IEmailParser wrapped;

      public PremailerEmailParser(IEmailParser wrapped)
      {
          this.wrapped = wrapped;
      }

      public MailMessage Parse(string emailViewOutput, Email email)
      {
          var message = wrapped.Parse(emailViewOutput, email);
          if (message.IsBodyHtml)
          {
              message.Body = PreMailer.Net.PreMailer.MoveCssInline(message.Body).Html;
          }                
          for(var i = 0 ; i < message.AlternateViews.Count ; i++)
          {
              var av = message.AlternateViews[i];
              if (av.ContentType.MediaType == MediaTypeNames.Text.Html)
              {
                  av.ContentStream.Position = 0;
                  var content = new StreamReader(av.ContentStream).ReadToEnd();
                  content = PreMailer.Net.PreMailer.MoveCssInline(content).Html;
                  message.AlternateViews[i] = AlternateView.CreateAlternateViewFromString(content, av.ContentType);
              }
          }
          return message;
      }
  }
}

@paulduran I found this from here.

I found a bug: if the email has an image then it won't be included.

remove this:

message.AlternateViews[i] = AlternateView.CreateAlternateViewFromString(content, av.ContentType);

add this:

var av2 = AlternateView.CreateAlternateViewFromString(content, av.ContentType);
foreach (var lr in av.LinkedResources) { av2.LinkedResources.Add(lr); }
message.AlternateViews[i] = av2;

Weird though my message.IsBodyHtml is always false, but the code works for some reason. Saved me lots of time, thanks!

@denisz1 thanks for the tip! We haven't needed to use images yet but your mod will certainly help when we do