Recently, Verizon and Comcast have been blocking port 25 causing our private mail server to stop functioning. Additionally, a lot of ISPs just started blocking any mail coming from any IP in the address block of cable modems.
So we started laundering our mail through a 3rd party service called DNSexit. Now McAfee's MAPS anti-spam system tells us that they are blocking DNSExit for spam.
Essentially, we are finding ourselves increasingly cut off from sending any outgoing mail. What is a small company supposed to do if you want to host your own mail?"