Re: Which Service Is Denying Relaying? - relaying denied 550 5.7.1
I see. For Comcast you would need to change the port for it to work.
For your web hosting provider can you send any emails? Do you get some reasonable limit out (50,100?) before you get blocked? I checked their web site and they don't seem to have much of anything for online documentation.
I gave uninets.net a quick call at this point.
From uninets.net technical support the response was that they are not aware of any number of messages limit, but that they would not be surprised if it existed. To relay through the server from off network (Comcast) configure smtp-auth and use port 25. You do not need to use an alternate port for their smtp-auth service.
I think this is where you are running into trouble since Comcast blocks outbound port 25. You need an SMTP server which does smtp-auth on an alternate port such as 587 so you can connect from anywhere, but your software is lmiting you to port 25.
If you do not want to change software, from what I can tell you will need to change your SMTP server settings to match the internet connection you are using when trynig to send the mailing lists.
-Raymond