Thanks for pointing me in the right direction. My IP address is on Spamhaus ZEN PBL list. One suggestion was to turn on SMTP authentication, but I had already enabled that in my outgoing mail settings in Outlook so that must not be the problem. There's a lot more to read and digest on the Spamhaus FAQ page.
Sorry, but I don't know about checking whether my IP address has a PTR -- not even sure what that is?
Seems to me as though Suddenlink didn't clear my modem/router's IP address from there "not yet installed" list when they install it for me?
not even sure what that is?
PTR is the reverse look up for your IP address. Imagine IP addresses are like phone numbers and domains are people's caller ID info. Normally, DNS works by looking up the IP address for a domain so you can go to the website, kind of like calling 411 for a person's phone number. A PTR is used when you want to see the domain registered with a IP, like looking up a person's name if you had their phone number. Does that make sense? If not, try reading here.
