I have a question regarding the need for setting up reverse DNS on a static IP for outgoing email. We have an Exchange email server setup that will be utilizing a DSL connection. We have a static Public IP setup so that we can send and receive email. However the DSL provider does not allow us to setup a reverse DNS entry so that the static IP maps to the A record of our email server. It is best practice to have this in place but I'm wondering how likely we are to experience problems sending people outside of our organization email if the reverse DNS entry isn't setup? What are your thoughts?