Hi, I have a notebook that's been running Outlook 2007. All of a sudden the last week or so. I've been getting an error sending emails (receiving is ok). I get this error: Sending' reported error (0x800CCC78) : 'Unable to send the message. Please verify the e-mail address in your account properties. The server responded: 452. 4.1.0 temporary failure At first I figure ok.. temporary.. But now it's not temporary. It happens 6/10 times. On this notebook: I have Avast and Windows Defender running. I've disabled both and I still get the above error. Please can someone shed some light on how to fix this. Oh I've also did all the latest office update. So everything is current. Thanks in advance!