Re: [SLUG] Port blocking on Verizon

From: Paul Bransford (draeath@gmail.com)
Date: Wed May 05 2010 - 23:54:58 EDT


Front line techs handle 'the internets done gone and broke' - expect escalation for anything more involved with anything consumer level. It sucks, but there it is...

-- Sent from my Palm Pre
On May 5, 2010 10:46 PM, Paul M Foster <paulf@quillandmouse.com> wrote:

On Wed, May 05, 2010 at 05:59:27PM -0400, Mark Bishop wrote:

>

> Quoting Paul M Foster <paulf@quillandmouse.com>:

>

>> On Tue, May 04, 2010 at 03:45:13PM -0400, Paul M Foster wrote:

>>

>>> I feel silly asking this question, since I've been working with Linux

>>> for over 15 years. But I've just never had to deal with the issue

>>> before.

>>>

>>> Verizon FiOS (which I have) is, starting 8 June, going to block port 25

>>> for customers who don't use Verizon's mail servers (which I don't).

>>> Their alternate port is port 587. As I understand it, I'm supposed to

>>> change my settings to this port, and all will be cosmic.

>>>

>>> Here's the thing, though. I tender mail to my local mailserver, which

>>> connects to my internet mailhost via port 25. If I set my local

>>> mailserver to connect via port 587, I can see how this would avoid

>>> Verizon's port blocking. But my internet mailhost still wants to see a

>>> connection on port 25. So does Verizon, when it sees a connection via

>>> port 587 to an internet mailhost, then change the port to port 25 (which

>>> is what my internet mailhost wants)?

>>>

>>> Can someone explain how this works?

>>

>> I seem to have answered my own question. When sending email via port

>> 587, your internet mailhost must also accept mail on that port, or the

>> whole thing won't work. In other words, if Verizon blocks port 25 and

>> suggests instead port 587, your choices are: 1) get your mailhost to

>> accept email connections on port 587, or 2) use Verizon's mail servers

>> for your outbound mail. It's uncertain whether Verizon will accept email

>> where the return address isn't on their mail server, however.

>>

>> Paul

>>

>

> I can almost bet that isn't going to work unless they only block

> access based off src IP (since they know all their own IPs) but I am

> sure they didn't do it this way.

>

> Question: How do the other mail servers on the internet know to use

> 587 to deliver mail to your server? You are going to make me look at

> what 587 is aren't you :)

Well, I can tell you this: my mailhost on the internet won't listen on

port 587. They'll listen on port 26, if you insist. So I have a call

into Verizon to ask: 1) will you allow port 26, or 2) will you accept

mail with from addresses in a foreign domain?

(The funny thing here is that I called Verizon FiOS support and got this

girl and asked her the above two questions. Now, these are pretty simple

questions that any tech support person should know. But no, she got my

phone number and will supposedly call me back when she gets the

answer(s). Seriously? How can even front line techs not know the

answers to these questions? Argh.)

I checked with AuthSMTP, which I've used before, and they won't listen

on port 587. I'm still looking at other mail relay providers, but almost

all are more expensive.

All this goes away if I purchase a fixed IP from Verizon. Of course, a

fixed IP from a hosting provider is from $1 to $5 per month. But from

Verizon, I'm guessing a fixed IP is probably more like $20 to $50/month.

If I have to move hosting providers in order to make this work, I'm

gonna be cranky.

I wish I could get these guys on their TOS, but I'll bet there's some

clause in there that allows them to block ports whenever they like.

Grrr.

Paul

-- 

Paul M. Foster

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