MailWindow: Add Date header to email

Elwig/Helpers/Utils.cs

@@ -535,6 +535,7 @@ namespace Elwig.Helpers {
                     msg.From.Add(new MailboxAddress(App.Client.NameFull, App.Config.Smtp.Value.From));
                     msg.To.AddRange(member.EmailAddresses.OrderBy(a => a.Nr).Select(a => new MailboxAddress(member.AdministrativeName, a.Address)));
                     msg.Subject = subject;
+                    msg.Date = DateTime.Now;
                     var body = new Multipart("mixed") {
                         new TextPart("plain") { Text = text }
                     };

Elwig/Windows/MailWindow.xaml.cs

@@ -937,6 +937,7 @@ namespace Elwig.Windows {
                 Mouse.OverrideCursor = Cursors.Wait;
                 var subject = EmailSubjectInput.Text;
                 var text = EmailBodyInput.Text;
+                var date = DateTime.Now;
                 await Task.Run(async () => {
                     await Utils.AddSentMailBody(subject, text, EmailDocuments.Count);
                     foreach (var (m, docs) in EmailDocuments) {
@@ -944,6 +945,7 @@ namespace Elwig.Windows {
                         msg.From.Add(new MailboxAddress(App.Client.NameFull, App.Config.Smtp.Value.From));
                         msg.To.AddRange(m.EmailAddresses.OrderBy(a => a.Nr).Select(a => new MailboxAddress(m.AdministrativeName, a.Address)));
                         msg.Subject = subject;
+                        msg.Date = date;
                         var body = new Multipart("mixed") {
                             new TextPart("plain") { Text = text }
                         };