I previously used Comcast for my ISP. I experienced problems receiving emails. I called their customer help line and they assured me every email sent to my address went euither into my IN BOX or my "spam filter" email folders. So I got an copy of the particulars of an email that was not received by me. I called again and they again confirmed every email went either to my IN BOX or spam filter folders. I then read provided the evidence to the contrary. Oooops! After talking with the manager of the customer service group, she gave me the phone number for their "network security" group. In talking with the Comcast newtork security group, I learned that they outsource their "high level email network filter" responsibility to a third party that checks all incoming traffic to their email servers. They track email that they consider bad -- spam or virus infected, etc. -- and when the percentage gets to a certain level (not for public information), they refuse ALL email from that source. You can request that the Comcast network security group re-authorize this email service provider to allow it to be "approved" -- but when it again gets to a certain level of "bad" email coming in to Cioncast, they will again block that email server. I expect your experience with intermittent email problems is caused by this security protocol. Note that if you use email forwarding addresses tht don't check for spam/virus emails before forwarding or the sending ISP has a large number of users with no or ineffective PC firewall security whose PCs have been compromised and are sending tons of email spam unkown to the PC owners, you'll experience this problem since Comcast has a very large number of users and I'm sure many get emails send from Irish ISPs. Hope this isn't too techy for the problem to be understood. In any case, I left Comcast for this specific reason -- their "high lever network security email filter" through out the baby with the (bad email) bathwater.....