[Info-vax] pop mail change

[glen herrmannsfeldt]

Tom Linden <tom at kednos.company> wrote:
> On Tue, 26 Feb 2013 06:57:36 -0800, Stephen Hoffman  

(snip)
>>> Comcast is my connection and they are now blocking port 25 for
>>> outgoing.  

(snip)
>> Blocking TCP port 25 outbound from netblocks containing dynamic  
>> addresses and from netblocks that aren't hosting mail servers is common  
>> practice, and quite often good practice.

>> Blocking TCP port 25 from a static IP assignment is less common,  
>> however.  A static IP assignment is typical with mail servers, so you'll  
>> want to check with your ISP about the blocks.

(snip)

>> For sending outbound mail from an SMTP server on a network with an  
>> outbound TCP port 25 block, you'll either need to get the block removed,  
>> or establish a relay, and TCP/IP Services doesn't offer a  
>> submission-port relay feature.  Postfix does offer the ability to  
>> perform an authenticated relay, but I don't know off-hand if the Process  
>> Multinet stack does.  (I know Process has a transport shim for sending  
>> authenticated mail from the Mail client, but I don't know if the Process  
>> Multinet SMTP server can relay.)

>> Probably the easiest: Roll in a Linux box, or a Mac Mini Server running
>> OS X Server...

>> This all presumes the ISP ToS permits this stuff.  Not all do.

Well, when the ToS says "server" they really mean allowing others
to access it. As you note, the wording might not say that.
They might be able to tell from the signon, but the usual configuration
of a unix-like system is to queue the mail and then send it on.

> I guess I didn't adequately explain my situation.  I run my own mail  
> servers on VMS with TCPIP and mx.  I use Outlook as my pop client 
> on XP at home and connect through comcast to the internet.  

> These are dynamic IPs of course.  Comcast is blocking port 25 so 
> I don't get to my servers.  So what I would like is to change  
> from port 25 to 587 (as you corrected me) and my question related 
> to what I needed to do with TCPIP in order to permit me to send 
> outgoing pop mail through the server.  How do I configure it to 
> accept this?

Yes, I believe what he said was right. You configure a Linux or
OS X box to run postfix, which will then relay mail as 
appropriate. 

For a long time, I had a unix box relay mail out port 25. I set my
firewall to block port 25 except from the mail relay host, and
to block it coming in. That avoided any problem with malware trying
to send directly out port 25. (Smart malware would figure out where
the mail relay was.) 

The only one that I ever ran into that wouldn't accept mail that way 
was the school district that my kids went to school in. They blocked
comcast addresses, except for the actual comcast server. 

I then had a postfix forwarder, as described, but now I usually
just use the comcast web mail. The forwarder has to have a comcast
login, but it doesn't have to be the same one as you use.
(Comcast allows for something like six e-mail addresses.) 
Specfically, it doesn't, (last I knew) require the return address
to be the logged-in user. Well, even more it doesn't even require
the return address to be comcast.net.  (Last I knew.)

-- glen