File Being Used By .NET Mail - vb.net

Question

I wrote a simple program written to collect files, send the files, then delete said files. I am sending them via Email using System.Net.Mail
If Label6.Text = "" Then
mail.Attachments.Add(New Attachment(zipPath))
End If
'Enables SSL, if required
ssl = Provider.ssl
If skipAhead = True Then
ssl = True
End If
If ssl = True Then
SmtpServer.EnableSsl = True
End If
'Sends the email
SmtpServer.Send(mail)
'Allows the user to either keep testing, or quit.
If skipAhead = True Then
My.Computer.FileSystem.DeleteFile(unalteredPath)
My.Computer.FileSystem.DeleteFile(unalteredPath1)
My.Computer.FileSystem.DeleteFile(zipPath)
Else
Dim keepOpen As Integer = MsgBox("The Email was sent. You can keep testing if you would like to. Press ok to close, and cancel to keep testing", MsgBoxStyle.OkCancel)
If keepOpen = 1 Then
Close()
End If
End If
As seen in line 2, the attachment is added to the email, and I do not attempt to delete the attachment until after the email is sent, however when the code is running, it throws an error that the file is being used by another process.
I am also wondering if this could be lingering from the .zip being created itself. Here is the code that does that:
Public Sub Zipping()
'Copies files to the folder where they will be zipped from
My.Computer.FileSystem.CopyFile(unalteredPath, outputs & "\ExIpOutput.txt")
My.Computer.FileSystem.CopyFile(unalteredPath1, outputs & "\IpConfig.txt")
'Deletes the old output files
My.Computer.FileSystem.DeleteFile(unalteredPath)
My.Computer.FileSystem.DeleteFile(unalteredPath1)
'Starts the zip Sub
ZipFile.CreateFromDirectory(outputs, zipPath, CompressionLevel.Fastest, True)
My.Computer.FileSystem.DeleteDirectory(outputs, FileIO.DeleteDirectoryOption.DeleteAllContents)
End Sub
Here is the CreateFromDirectory sub:
Public Shared Sub CreateFromDirectory(sourceDirectoryName As String, destinationArchiveFileName As String, compressionLevel As Compression.CompressionLevel, includeBaseDirectory As Boolean)
End Sub
Is there something I'm missing here, or do I need to have the program sleep for a bit to let the email send, then delete the .zip file?

Answer 1

You can load the file into an array: File.ReadAllBytes(String) Method.
Then get a MemoryStream from that: How do I convert struct System.Byte byte[] to a System.IO.Stream object in C#?
And finally, you can use a MemoryStream for an attachment: Attach a file from MemoryStream to a MailMessage in C#.
As the data to be sent is in memory, you should be able to delete the file. Note that if there is a crash, the data is gone.
The examples are in C#, but if you have problems using the methods in VB.NET, please edit your question to show how far you've got and tell us what the problem is.

Answer 2

A better solution to this issue is to dispose the Attachment object that is locking the file. Any object you create that has a Dispose method should have that method called when you're done with the object and an Attachment is no different.
Dim fileAttachment As Attachment
If Label6.Text = "" Then
fileAttachment = New Attachment(zipPath)
mail.Attachments.Add(fileAttachment)
End If
'...
SmtpServer.Send(mail)
If fileAttachment IsNot Nothing Then
fileAttachment.Dispose()
End If