Hi, I have my isa server publishing an smtp server with an external address of x.x.x.153 My ISA server default ip is x.x.x.130 My PTR record pointing to my mail server is x.x.x.153 Why when I receive emails to an external account, do I see the ip x.x.x.130 in the header info? This scares me as it seems it could cause problems... I am looking at the header granted in the options in outlook, so it could be leaving some interaction between the mail servers out... Any thoughts on why this would occur?