[Info-vax] pop mail change

[Stephen Hoffman]

On 2013-02-26 14:17:27 +0000, Tom Linden said:

> I use Outlook as my pop client to TCPIP and mx as smtp
> Comcast is my connection and they are now blocking port 25 for
> outgoing.  They have switched to 995 and 465 for in and out, resp.
> 
> What steps do I need to take with tcpip to switch 110, 25 to these ports.
> Do I need to make any changes to mx?

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.

As for options if the ISP isn't willing to drop the blocks and wants 
you to relay, you could roll in an operating system and a server that 
runs Postfix or analogous mail server (or try the Lamson project SMTP 
server that's based on Python, and see if that works on OpenVMS), or 
migrate to the Process Multinet IP stack.  Not good choices.

For remote mail clients connecting to your mail server, it's common to 
see these same port blocks effect mail submissions via TCP port 25.  
This means switching the client from TCP port 25 to (usually) TCP port 
587 and setting up authentication, and TCP/IP Services doesn't support 
the alternate submission port, so you'll either need to change to a 
different mail server (whether on or off of VMS), or to use a VPN to 
reach the mail server.

TCP port 465 is not as commonly used as is TCP 587 ESMTP port.  TCP 995 
is POP via SSL.

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.

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