# Reverse-Fetchmail

## MacMasta

Right, so here's the plan:

I currently get my e-mail over a classic ISP pop3 account, and send using a classic ISP smtp account.

Mostly to learn, I'm going to set myself up an e-mail and imap server, so I can keep track of my e-mail from both my laptop and desktop at the same time. (Easy enough)

However, I don't want to bother with getting a domain, or changing e-mail addresses, or anything else - I want the change to be completely transparent to the outside world, so people continue to send to my current pop3 account, and continue to receive from my current smtp account.

Therefore, I figure I'll do:

 isp -> fetchmail -> postfix -> imap -> evolution on the incoming side.

However, for the outgoing side, I have:

 evolution -> imap -> postfix -> xxx -> isp.

I need a piece of software that will fulfill the duties of fetchmail, but in the outgoing direction.

Will postfix (or insert MTA here - it can change) do this for me? If not, what do I need?

Thanks!

~Mac~

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## lx

I believe it can, used it in the beginning but now I'm using it to send my message's myself (all over the world, ha). something with relayhost=.... (but maybe your ISP doesn't allow it (relaying not allowed)) in postfix config.

Hope it's get you on your way, Alex.

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## klieber

 *MacMasta wrote:*   

> However, for the outgoing side, I have:
> 
>  evolution -> imap -> postfix -> xxx -> isp.

 

As long as your ISP doesn't block outbound port 25, just use postfix as your MTA.  That's what it's designed to do, after all.   :Smile:   Make sure you spend some time understanding the postfix config file (I use exim, so I can't be of much help here) but you should be able to configure it to send all outgoing email with your correct email address, etc.  Some things to be particularly careful of:

making sure postfix sets the correct reply-to and envelope header informationmaking sure it's not set up as an open relay

--kurt

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## alec

There's a postfix option called relayhost that will allow you to set your ISP's mail server.  However, most of the time you'll be able to use postfix just fine on its own - I am :)

The only problem you might encounter would be the previously mentioned blocked port and also some domains (one example is sourceforge) that have spam-blocking lists that exclude dial-up users.

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## lx

 *alec wrote:*   

> that exclude dial-up users.

 

They probably check if you are pingable, pffff thkx IP for giving me static IP with DNS-name.

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## alec

There are actually lists that block dial-up users.

From http://mail-abuse.org/dul/ :

 *Quote:*   

> So what is the DUL(SM) anyways?
> 
> The MAPS DUL(SM) is a list of known dial-up or dynamically assigned pools of IP addresses. Mail administrators can use the DUL(SM) to prevent users on those IPs from sending e-mail to their servers, what I call e-mail trespassing. So far, the largest reason I've seen for users to do this is to send unsolicited e-mail, aka: spam. The list is available as a DNS zone arranged similar to the MAPS RBL(SM), so administrators could adapt RBLSM-aware software to use the DUL(SM) quickly. It is also available as a list of networks in CIDR format (Classless Inter-Domain Routing) for other uses, such as programming TCP Wrappers and to look up addresses.
> 
> The MAPS DUL(SM) Project is about preventing e-mail trespassing, by making this list of dial-up networks available to mail administrators, and by allowing dial-up ISPs to prevent trespass spammers from using their networks by volunteering dial-up information to us. 

 

What they're trying to do is to prevent the spammers who get a cable modem and set up their own MTA to directly send mail to people.

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## lx

 *alec wrote:*   

> There are actually lists that block dial-up users.
> 
> ...
> 
> What they're trying to do is to prevent the spammers who get a cable modem and set up their own MTA to directly send mail to people.

 

Let's hope I'm not in such a list (I've got a static IP and I'm NOT I REPEAT NOT a spam sender, I'm more the opposite, a spam attractor   :Laughing:  ).

Cya lX.

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## klieber

 *lx wrote:*   

> Let's hope I'm not in such a list

 

The list isn't maintained on a user-by-user basis.  They look at blocks of IP addresses that the major ISPs use (AT&T, PacBell, etc.) and dump all those IP blocks into the list.  So, it doesn't matter if you've ever sent a single spam mail or not -- if your ISP's IP blocks are on the list, you're part of it, too.  Not exactly fair, I realize, but not much you can do about it.

I've run afoul of the list on a few occasions -- Cray (supercomputers) uses it for some reason and some other corps do as well.  In those cases, I simply use a backup SMTP server -- it's a bit of a pain to send the mail to a separate SMTP server, but since it doesn't happen all that often, it's not that big of a deal.

--kurt

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## lx

 *klieber wrote:*   

> They look at blocks of IP addresses that the major ISPs use (AT&T, PacBell, etc.) and dump all those IP blocks into the list.  So, it doesn't matter if you've ever sent a single spam mail or not -- if your ISP's IP blocks are on the list, you're part of it, too.  Not exactly fair, I realize, but not much you can do about it.

 

That's freakin unfair, nothing I can do about it, well see, where are the rights for a law obeying interneter. We'll I'm gonna,....................., rebuild my whole system out of silent protest, that'll teach them.   :Cool: 

Thanks for your answer, never happend to me but now I am warned if some message bounces, thkx lX

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## alec

Yes, it's unfair, but it is a good way of blocking spam.

One thing to remember is that all of these lists are voluntary and that (hopefully) the admins know what they're doing.  Statistically, however, little to no mail of any useful importance will come from dial-up addresses, and those that know how to set up a MTA probably know how to switch to their ISP's server.

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## rizzo

Yeah I don't use the DUL on my mail server, because of the many unreliabilities it finds.  I use the relays and blackholes list from mail-abuse.org.

I know slashdot had an article about all the problems with false positives in the DUL.

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