Originally Posted by UAVirgin
My ISP is Earthlink on a Qwest provisioned DSL line. Yes, earthlink blocks port 25 which is why I use port 587 directly to my hosting provider. It is not a port problem as the random accounts that get to be the sender are all on port 587, just different servers and or IP addresses.
FWIW, the local MSO is Mediacom, not Comcast and I don't have anything to do with them.
SMTP email still has to pass through
something at the ISP before it gets to your hosting provider, no?!
Someone tell me I'm mistaken, but it's like my SBC DSL. They block SMTP port 25 -- although they will open it for your ID if you ask, as I have done. No matter if I use their port 25, or their "port XXX" for sending SMTP, it still goes
through that SBC DSL provider port
before it ever gets to my MSN email account's SMTP authentication server, or my GMail SMTP authentication server, or your hosting provider's port 587.
I still don't think that it's Outlook's issue... at least not the way you are thus far filling in the blanks here for us.