I am getting delivery failures, which never occurred before until I migrated to another server few months ago.  I have setup abuse@domain.com for the account that is having delivery failures, here is info 
 

Failed Recipient: recipient@gmail.com
Reason: Remote host said: 601 Attempted to send the message to the following ip's: 
	74.125.28.27, 2607:f8b0:400e:c04::1b, 74.125.193.26, 2607:f8b0:4001:c05::1a, 
	173.194.219.26, 2607:f8b0:4002:c03::1a, 173.194.207.27, 2607:f8b0:400d:c09::1a, 
	74.125.141.27, 2607:f8b0:400c:c06::1b

Failed Recipient: info@regulardomain.com
Reason: Remote host said: 601 Attempted to send the message to the following ip's: 
	207.46.163.215, 207.46.163.170, 207.46.163.247, 66.96.140.124, 
	66.96.140.125

suggestions greatly appreciated.  I am also looking for configuration assistance for setting up and maintaining our smartermail installations.