As far as AD site links go, we have our site links set (which includes all our sites);
default site link: 100 cost, and 15 min replication interval.
SMTP link; 100 cost and 180 min interval.
As I understand it, SMTP is used to route messages between sites.
Are the IP site links used?
Do we need to change the SMTP (or IP) settings? i.e. cost and interval..?