I have recently migrated from Exchange 2013.  I have several internal IP addresses that I would like to allow to send email from via applications and also a scanner.  I have set up a receive connector and allowed the internal IP range and anonymous access and have verified that it works fine.  

It seems the anti-spam system seems to to block the email as I get a notification on the administrators account of failed delivery. I could allow the spam system to bypass the domain but this would allow any spam with the domain name to come through.

Any ideas?

Hi Adam,

How about the suggestion from Ed?

I also suggest keep the original settings of Anti-Spam and add these applications into IP Allow list.

For more information as below:

Understanding Anti-Spam and Antivirus Mail Flow

https://technet.microsoft.com/en-us/library/aa997242.aspx?f=255&MSPPError=-2147217396

Configure Anti-Spam Settings on Mailboxes

https://technet.microsoft.com/en-us/library/bb123559(v=exchg.150).aspx

Thanks