Please note that "Recent" messages are emails which arrived during your current session. Emails which arrived between your current session and last session are not marked as recent. Therefore you probably need to check "Unread" emails.
Following code should do the work:
Dim client As New Imap
client.Connect("imap.gmail.com", 993, Nothing, ImapSecurity.Implicit)
client.Login(strUName, strPWD)
client.SelectFolder("Inbox")
Dim list As ImapMessageCollection = client.Search( _
ImapMessageSet.All, _
ImapListFields.MessageStructure Or ImapListFields.UniqueId, _
ImapSearchParameter.Unread)
For Each message As ImapMessageInfo In list
If message.HasAttachment Then
Dim mail As MailMessage = client.GetMailMessage(message.UniqueId)
For Each attach As Attachment In mail.Attachments
attach.Save(message.UniqueId & " - " & attach.FileName)
Next
End If
Next