Successfully Configured Email Filtering
For those looking to allow sending and receiving emails to and from specific domains, follow these steps:
Navigate to:
System > Configuration > Global Filter Maps > Regex Maps
Add the desired domains using appropriate regex patterns.
Add
Envelope Sender Blacklist
global_smtp_from_blacklist.map
/^[\w.-]+@(?!domain1.com$|domain2.com$).+/i
Recipient Blacklist
global_rcpt_blacklist.map
/^[\w.-]+@(?!domain1.com$|domain2.com$).+/i