efa-project.org

I'm still using EFA 3 and looking at EFA 4

Currently I have 6 domains - 4 of which are ours - single appliance
I read through the License terms - but not sure if I need to purchase any licensing
I'm not sure I understand the information - I think it relates to distribution

I'm providing a filtering service 2 others & make a small charge for "Support" - 6 users + 15 users
As the numbers are small its probably a overkill for an EFA4 appliance

Do I need a license for any component?

No, it's all open source.

However, if you're benefiting from the software, you may wish to consider a donation to the EFA or MailWatch developers.

@shawniverson, do you have any thoughts on that?

Just bear in mind the restrictions of using DCC. https://www.dcc-servers.net/dcc/