I already have smtp sasl_auth setup.
We have some users with simple forwarded addresses and some with POP
accounts. Some of these POP accounts send through their own ISP.
1. Will I need to add a SPF record to each DNS record on our
nameservers, assuming it will be used as a from address for email?
2. Will the users using forwarding be able to use their domain as the
from address when replying while sending through their ISP? Or would
that ISP need to add a record for that sender?
3. Will POP account users need to only send through our server to make
use of the SPF record, assuming they are using their domain in the from
address?
Seems not much is covered anywhere from the hosting point of view.
Best,
John Hinton