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Date:      Sat, 20 Aug 2005 09:20:06 -0500
From:      "Jay Banks" <jay.quest4@gmail.com>
To:        <freebsd-isp@freebsd.org>
Subject:   Re: Workarounds for blocked port 25 on outgoing e-mail
Message-ID:  <003601c5a592$4965e530$15f9e204@4BANKS>
References:  <003f01c5a517$ee377590$81f9e204@4BANKS> <56484ca2cf96b4011c66d9146cc47e49@gothic.net.au>

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From: "Sean Winn" wrote:
> You don't have to use your POP3 provider's SMTP server just to send 
> from their address. If you want to use their services (eg. they may do 
> archiving or reformatting with a standard footer or something similar) 
> that's the only necessity for using them.

I don't quite understand what you are saying. I have multiple POP3
accounts with a virtual host and my servers at work, etc. I can get 
e-mail from them all day long, but every ISP I use blocks my attempts 
to send through them. I get "no socket" errors when I try and connect.

Same thing for our company employees not physically located
in our area. They can get e-mail from our server (MS Exchange
for them) just fine, but none of them can send mail through it. Not 
because of something on my side, but because of the ISP they use. 

I would like to solve the problem for the above reasons, but it
would also be nice to offer POP3 access to customers and
know that they could use it from any location without having
to resort to some web-based front end.
 
> Port 587 is the mail submission port, and is supported by sendmail, 
> postfix, exim etc with little problems. The only client I'm aware of 
> that makes it difficult to use a different port is Eudora, and even 
> then they document a way of doing it (changing the eudora.ini file).

I just played around with this for a little bit and it doesn't work for
POP3 servers through esosoft.com. Not sure if it is them or my ISP,
though.

Doug Hardie wrote:
> Blocking external use of port 25 is a simple, but misguided, approach  
> to spam control.  It creates too many problems for people who are  
> properly using mail.  The better approach is to require the use of  
> SMTP-AUTH (preferrably with TLS) before permitting any mail routing.   
> If all MTAs did that there would be no need to block port 25.

I talked to the guy at my ISP about why they do this. Maybe I
will e-mail him and get him to explain his rational for this and
forward it here. If I remember correctly, it is because users (they 
have over 3000) are finding open mail relays and SPAMing through
them. So even though the SPAM didn't go through their mail
servers, the ISP's IP address showing up in the headers of
SPAM are getting them threatened by blacklist services.

Now maybe you could blame this on SPAM, but you also
have to see the danger of blacklists here. After all, it wasn't
my ISPs fault that someone else left an open relay on the
Net. The blacklists maintainers should be going after the
open relay, not the ISP, in my opinion.

Logan wrote:
> Your access provider should be able to handle outbound
> email for you with very little trouble. It's probably as easy as
> asking what they recommend as the outbound/smtp mailserver
> for you.

Honestly, there is a way around this. My ISP can add
the IP address of my hosted POP3 servers into a
permit list. It took me weeks, however, to get them to
do this. It worked for about a week, and then I guess 
they backed up, restored something, or upgraded
something, and it quit working. I got tired of jacking
with them and just started using Google's POP3
server for outbound e-mail, which used a different
port than port 25. I pay money for POP3 accounts
that come with some hosted web pages, however,
and I would like to be able to use them.

I asked the DSL providers of one of our employees
in another town to unblock port 25 for that employee...
and the guy **laughed** at me.

Cody Baker wrote:
> The forth option, commonly called "SMTP after POP/IMAP" is 
> a bit more of a hack in my opinion, but requires no additional
> configuration on the users end 

That is what I setup with my sendmail/popa3d configuration.
And honestly, after looking at the alternatives, this seemed
to be the easiest route to go. It took me about half a day
to figure it out. This is also what my hosted POP3 accounts
use, as I have to check e-mail before I can send it
through them, too. Honestly, looking at some of the
other solutions made my eyes cross a little bit. :)

Thanks

Jay Banks














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