Chapter Objectives

Chapter Objectives Introduction to ASP.NET, Second Edition

Sending E-Mail from the Web Application • Security and Privacy Issues Related to E-mail • HTML-based • Viruses • Spam • Authorized users send e-mail Introduction to ASP.NET, Second Edition

The E-Mail Server • E-mail server - SMTP server • Simple Mail Transfer Protocol (SMTP) • Protocol, or set of rules • Used to transfer mail between servers • Default folders • Pickup, Queue, Badmail, Drop, Route, Mailbox, SortTemp • C:\InetPub\MailRoot • Verify the service is running • Administrative Tools - Open Services • Runs on port 25 Introduction to ASP.NET, Second Edition

The E-Mail Server (continued) Introduction to ASP.NET, Second Edition

Configuring the E-Mail Server • Use MMC • Default SMTP Virtual Server • General Tab • Log Files • C:\WINDOWS\Sytem32\Logiles\SmtpSvc1\ • W3C Extended Log File Format • Advanced button - IP address Introduction to ASP.NET, Second Edition

Configuring the E-Mail Server (continued) Introduction to ASP.NET, Second Edition

Configuring the E-Mail Server (continued) • Access Tab • Authentication button • Anonymous access • Basic authentication • Integrated Windows Authentication • Similar to IIS Introduction to ASP.NET, Second Edition

Configuring the E-Mail Server (continued) • Messages Tab • Size of message • Session size • Total size of all the message body sections within a single connection • Number of messages per connection • Number of recipients per connection • E-mail address for Non-delivery Report • C:\Inetpub\mailroot\Badmail Introduction to ASP.NET, Second Edition

Configuring the E-Mail Server (continued) • Delivery Tab • How the message is delivered • If can’t be sent - number of minutes to wait before resend • Outbound Security • Configure users and authentication • Require encryption (TLS) - more secure then SSL • Outbound Connections • Limit number of messages, time-out • Limit number of connections per domain • Change port number Introduction to ASP.NET, Second Edition

Configuring the E-Mail Server (continued) • Advanced – Figure 12-8 • Configure servers that can send or relay messages • Prevent invalid domain address in Mail From line using Masquerade domain • Hop count - number of servers permitted to pass through • Smart host - a virtual server which may be more direct or less costly than sending it directly to a domain Introduction to ASP.NET, Second Edition

Configuring the E-Mail Server (continued) • LDAP Routing Tab • Lightweight Directory Access Protocol • Primary protocol for Active Directory • Directory service that stores information about objects on a network • Security Tab • Who can change settings - default administrators group • Only trusted users to “alter” settings • Domains • E-mail at tarastore.com and tarastore.net sent to same server Introduction to ASP.NET, Second Edition

E-Mail Objects • .NET Mail classes • CDONTS Objects - communicate with SMTP server • C:\WINDOWS\system32\cdonts.dll • Places message in the Pickup folder - or by hand • SMTP places message into Queue folder • If local recipient - places into Drop folder • If remote account - sends message to another server • If rejected or returned, places in Badmail folder • Creates Non-Delivery report (NDR) Introduction to ASP.NET, Second Edition

E-Mail Objects (continued) Introduction to ASP.NET, Second Edition

The .NET Mail Classes • System.Web.Mail namespace • MailMessage class - construct an email message • MailAttatchment class - identify a file (attachments) • SmtpMail class - send the e-mail message Introduction to ASP.NET, Second Edition

The MailMessage Class Properties • MailFormat enumeration - format • MailFormat.Html, MailFormat.Text • MailPriority enumeration - importance • MailMessage.Normal, MailMessage.High, MailMessage.Low • MailAttachment class - construct an e-mail attachment • Filename - attachment location as string - drive, path, filename • MailMessage.Attachments - list of attachments • MailEncoding enumerator • MailEncoding.UUEncode default • MailEncoding.Base64 - binary encoding such as graphics Introduction to ASP.NET, Second Edition

The MailMessage Class Properties (continued) • MailMessage.To - recipient; multiple recipients separated with semi-colon • MailMessage.From - address of the sender • MailMessage.Subject - subject line • MailMessage.Body - body • MailMessage.Cc - a semicolon-delimited list • MailMessage.Bcc - semicolon-delimited list • MailMessage.UrlContentBase - URL base of all relative URLs used within the HTML - encoded body • MailMessage.UrlContentLocation - identify the location of content within message Introduction to ASP.NET, Second Edition

The MailMessage Class Properties (continued) • SmtpServer – change the SMTP Server from default SMTP Virtual Server to another server • Send method creates the message • Writes it to the Pickup folder • Eventually it’s moved to the Queue folder SmtpMail.Send("sender@sender.com", "recipient@recipient.com", "Subject", "Message") Introduction to ASP.NET, Second Edition

Sending an E-Mail Message from an ASP.NET Web Page • Create Chapter12 project and import files • Email_SendSingleMessage.aspx • Import namespaces Imports System.Web.Mail • Create mail object, set properties, send message • Release variables • View page in the browser • View message in Drop folder • Folder varies with your system Introduction to ASP.NET, Second Edition

Sending an E-Mail Message from an ASP.NET Web Page (continued) Dim MM As New MailMessage() MM.From = "[your_email@your_address.edu]" MM.To = "[your_email@your_address.edu]" MM.Subject = "CDONTS Exercise" MM.Body = "I have completed the CDONTS exercise" MM.BodyFormat = MailFormat.Text MM.Priority = MailPriority.Normal SmtpMail.SmtpServer = "[Server name]" SmtpMail.Send(MM) MM = Nothing Introduction to ASP.NET, Second Edition

Sending an E-Mail Message from an ASP.NET Web Page (continued) Introduction to ASP.NET, Second Edition

Troubleshooting E-Mail Messages • “The SendUsing configuration value is invalid" • Solution: • Reconfigure the SMTP settings programmatically and assign a server name before the message is sent. • "The server rejected one or more recipient addresses." • Unable to relay for [your-email@your_address.edu] • Solution • Change relay settings - allow your server to relay messages • Only allow messages from your computer to relay messages • Use exception handling and error messages • Read Non-Delivery report (NDR) Introduction to ASP.NET, Second Edition

Troubleshooting E-Mail Messages (continued) Introduction to ASP.NET, Second Edition

Storing and Retrieving Data in the Web Server’s File System • System.IO namespace • Interact with the file system • Classes: • File, FileStream, and Directory • To create, read, and delete files • Newer classes – FileSystemInfo • Access to DirectoryInfo and FileInfo classes • View Class Browser Application Introduction to ASP.NET, Second Edition

Storing and Retrieving Data in the Web Server’s File System (continued) Introduction to ASP.NET, Second Edition

Working with Directories • DirectoryInfo class • Access to properties Dim DD As DirectoryInfo = _ New DirectoryInfo("C:\Inetpub\wwwroot\Chapter12\") Label1.Text = DD.FullName • Other properties • Attributes, CreationTime, Exists • LastAccessTime, LastWriteTime • FullName, Extension, Name, Parent, and Root Introduction to ASP.NET, Second Edition

Working with Directories (continued) • Iterate through DirectoryInfo Dim MySubDirList As String Dim SubDir As DirectoryInfo For Each SubDir In DD.GetDirectories() MySubDir &= SubDir.Name & " " Label2.Text = MySubDirList Next Introduction to ASP.NET, Second Edition

Working with Directories (continued) • Iterate through FileInfo Dim MyFileList, MyPath As String MyPath = TextBox1.Text Dim MyFile As FileInfo For Each MyFile In DFL.GetFiles Select Case MyFile.Extension Case ".aspx" MyFileList &= _ "<a href='" & MyFile.Name & "'>" & _ MyFile.Name & "</a> " Case ".vb", ".resx" Case Else MyFileList &= MyFile.Name & " " End Select Next Label3.Text = MyFileList Introduction to ASP.NET, Second Edition

Working with Directories (continued) • DisplayChapter12Dir.aspx • DisplayDirectoryInfo function Dim DD As DirectoryInfo = _ New DirectoryInfo(MyPath) lbl1.Text = DD.FullName lbl2.Text = DD.Name lbl3.Text = DD.Attributes lbl4.Text = DD.CreationTime.ToShortDateString lbl5.Text = DD.LastAccessTime.ToShortDateString lbl6.Text = DD.LastWriteTime.ToShortDateString lbl7.Text = DD.Root.Name lbl8.Text = DD.Parent.Name lbl9.Text = DD.Exists lbl10.Text = GetLength(DirSize(DD)) Introduction to ASP.NET, Second Edition

Working with Directories (continued) Introduction to ASP.NET, Second Edition

Creating and Deleting Directories • DirectoryInfo - to create and delete directories • CreateSubdirectory method - create a new directory • Pass the name of the directory • CreateDir.aspx • Buttons to create and delete directories • DisplayDirectory function • Retrieve the Users subdirectory list • c:\Inetpub\wwwroot\Chapter12\Users Introduction to ASP.NET, Second Edition

Creating and Deleting Directories (continued) • System.Exception • System.IO • IOException • DirectoryNotFoundException - directory does not exist • PathTooLongException - exceeds 248 characters • FileNotFoundException • Security.SecurityException - don’t have permission • System.ArgumentException • Create a directory with invalid characters <>*?” or \\ Introduction to ASP.NET, Second Edition

Creating and Deleting Directories (continued) Dim DDL As DirectoryInfo = _ New DirectoryInfo(MyPath) Dim SubDir As DirectoryInfo Dim MyHash As New Hashtable For Each SubDir In DDL.GetDirectories() MyHash.Add(SubDir.Name, SubDir.Name) Next DropDownList1.DataTextField = "Key" DropDownList1.DataValueField = "Value" DropDownList1.DataSource = MyHash DropDownList1.DataBind() Introduction to ASP.NET, Second Edition

Working with Directories (continued) • btnCreate_Click procedure Dim DD As DirectoryInfo = _ New DirectoryInfo(MyPath) DD.CreateSubdirectory(TextBox1.Text) • btnDelete_Click procedure Dim DD2 As DirectoryInfo = _ New DirectoryInfo(MyPath & _ DropDownList1.SelectedItem.ToString) Label1.Text = "The " & _ DropDownList1.SelectedItem.ToString & _ " directory was deleted." DD2.Delete() Introduction to ASP.NET, Second Edition

Working with Directories (continued) Introduction to ASP.NET, Second Edition

Creating and Reading Files from an ASP.NET Page • FileInfo class • Common Properties • Attributes, CreationTime, LastAccessedTime, LastWriteTime • Name, FullName, and Exists • Attributes – (Right click on file and select Properties) • Hidden, Archive, ReadOnly, System • Methods • CopyTo, MoveTo, Delete • CreateText method • Returns StreamWriter object and open file for editing • Create method • Wrapper for the functionality of File.Create • Uses FileStream object not StreamWriter object Introduction to ASP.NET, Second Edition

Creating a Text File • CreateFile.aspx • btnCreate_Click - creates the FileInfo object • Create StreamWriter object to create the file and open it for writing Dim MyFile As String = MyPath & TextBox1.Text Dim MyFileInfo As FileInfo = New FileInfo(MyFile) Dim SW As StreamWriter = File.CreateText(MyFile) Introduction to ASP.NET, Second Edition

Creating a Text File (continued) • Write the contents to the file - Write and WriteLine SW.Write("This file was ") SW.WriteLine("created by: ") SW.Write("[Your Name]") SW.Write(vbCrLf) SW.WriteLine("on " & Now.Date.ToShortDateString) SW.WriteLine() SW.WriteLine() SW.Write(TextBox1.Text) SW.Close() MyFileInfo = Nothing Introduction to ASP.NET, Second Edition

Creating a Text File (continued) • btnDelete_Click event procedure Label1.Text = "The " & TextBox1.Text & _ " file was created successfully." Dim MyFileInfo As FileInfo = New FileInfo(MyFile) Label1.Text = "The " & _ DropDownList1.SelectedItem.ToString & _ " file was deleted." MyFileInfo.Delete() MyFileInfo = Nothing Introduction to ASP.NET, Second Edition

Creating a Text File (continued) • btnDisplay_Click • Retrieves file - FileInfo object and opens file with OpenText • Returns StreamReader object • ReadToEnd - reads entire file line by line until end of file Dim MyFileInfo As FileInfo = New FileInfo(MyFile) Dim SR As StreamReader = MyFileInfo.OpenText() Label3.Text = SR.ReadToEnd SR.Close() SR = Nothing Introduction to ASP.NET, Second Edition

Chapter Objectives