Google Apps, Connect Email

Trying to use Google Apps to send a notification to my google mail account, nzbdrone seems to choke on the gmail response… The configuration is simple, smtp host is aspmx.l.google.com on port 25 with a from and to name specified. The rest are blank since this gateway does not require authentication as long as the “To” user is a google apps user as per https://support.google.com/a/answer/176600?hl=en

Here is the log from nzbdrone… the app seems to choke on the response and throw an exception.

System.Net.Mail.SmtpException: Mailbox unavailable. The server response was: 5.7.1 [ 12] Our system has detected that this message is
at System.Net.Mail.DataStopCommand.CheckResponse(SmtpStatusCode statusCode, String serverResponse)
at System.Net.Mail.DataStopCommand.Send(SmtpConnection conn)
at System.Net.Mail.SmtpConnection.OnClose(Object sender, EventArgs args)
at System.Net.ClosableStream.Close()
at System.Net.Mail.MailWriter.Close()
at System.Net.Mail.SmtpClient.Send(MailMessage message)
at NzbDrone.Core.Notifications.Email.EmailService.Send(MailMessage email, String server, Int32 port, Boolean ssl, NetworkCredential credentials) in m:\buildAgent2\work\328d72309b633a8\src\zbDrone.Core\otifications\Email\EmailService.cs:line 59

Are you sending from a static IP and have a valid SPF record configured?

This line in the article you linked pretty much sums it up though:
If your device or application supports SSL - connect to smtp.gmail.com on port 465. drone does, you should use that.
Why not use an username and password and save yourself some extra configuration?