Re: exim4: how to handle other addresses on my ISP?
* Chris Metzler <cmetzler@speakeasy.net> [061115 00:39]:
>
> Hi,
>
> I'm having trouble configuring exim4. My situation -- that is, what I
> want exim4 to do -- *can't* be that unusual; so I'm sure I'm missing
> something fairly obvious. But I've played around with exim4's
> configuration via "dpkg-reconfigure exim4-config" a zillion times and
> cannot get there. I've Googled and skimmed the exim4 FAQ without much
> success yet -- lots of stuff, but nothing that looks obviously like
> the solution here. Next up is digging into the exim4 specification in
> detail. I really don't want to that if I don't have to -- I mean, if
> that's what I have to do to solve this problem, I will; but I'm hoping
> that I'm just missing something with "dpkg-reconfigure exim4-config"
> and this can be solved more easily than skipping sleep, since right now
> I'm effectively working 15 hours a day and sleeptime is pretty much the
> only free time I have anymore.
>
> Here's my situation and what I want:
>
> 1. I have a machine with no domain of its own, in the sense that I
> haven't registered a domain or anything like that. My ISP is
> speakeasy.net. Outgoing email goes to a smarthost. Incoming email
> is pulled in by fetchmail and handed off to exim4.
>
> 2. Various users on this machine have email adresses registered with
> the ISP of the form some_user_name@speakeasy.net. When one of my
> local users sends an outgoing email, exim4 appends "@speakeasy.net"
> to the local username.
>
> 3. Likewise, if you were to send email to one_of_my_users@speakeasy.net,
> fetchmail on my machine should eventually grab it and pass it to exim4 here.
> This apparently means that when I've configured exim4 using dpkg-
> reconfigure, I need to tell exim4 that "speakeasy.net" should be added to
> the list of domains for which this machine should consider itself the final
> destination. If I don't do that, then when exim4 receives from fetchmail
> an email for one_of_my_users@speakeasy.net, exim4 immediately passes that
> email back on to the ISP's smarthost (because we aren't a final destination
> for "@speakeasy.net"), and around and around we go.
>
> 4. But if I do that -- if I tell exim4 that "speakeasy.net" should be
> added to the list of domains for which this machine should consider itself
> the final destination, then that means I'm unable to send email to other
> users of this ISP that have nothing to do with my machine (since they all
> have addresses like some_nonlocal_user@speakeasy.net). Right now, if I
> send an email to some_nonlocal_user@speakeasy.net, exim4 notes that it's
> been told that *I'm* the end destination for email to the domain
> speakeasy.net, and cheerily reminds me that there's no one on this
> machine by that username.
>
> Is there a simple solution to this? Or is it time for me to roll my
> sleeves up and learn exim4 in more detail? If someone can clarify what
> I'm doing wrong through dpkg-reconfigure, or point me at some helpful
> documentation, I'd be very grateful.
I am no expert, but I had a similar problem. And I shall be grateful
for correction from those who are experts. I discovered that I was
making difficult a problem which is simple.
The typical home or small business user needs only a small fraction of
the capabilities provided by a mail transfer agent (MTA) such as
Exim4. But little, if anything, is to be gained by switching to a
less-capable alternative. You simply need to understand that, in the
context of the LAN of a home, domitory, or small business, Exim4 need do
nothing more than serve as a mechanism for handing off outgoing mail
from the machines in the LAN to the smarthost of your choice.
If the smarthost is, for example, the mail server of the outfit which
hosts your commercial web site, it may be necessary to have Exim
rewrite headers so that unqualified addresses are replaced with a
valid address, and it may be necessary to configure Exim to
authenticate with that server. But if you are using as smarthost the
SMTP server of your ISP, rewriting and authentication may not be
necessary.
When filling in the blanks in the Exim4 configuration dialogue of the
Debian installer, don't worry as to whether the headers accurately
reflect the particular sender. All you need to do is get Exim
configured so that the smarthost accepts your outgoing mail.
The selection of the proper From: header for outgoing mail is the duty
of your mail user agent (MUA); the MUA may be Mutt, Gnus, Balsa,
Sylpheed, Thunderbird, etc. Read the documentation concerning
multiple send 'personas' or 'personalities'.
The sorting of incoming mail for multiple users or multiple
personalities is the function of a mail delivery agent (MDA) such as
maildrop. Exim has no role to play with respect to incoming mail
which originates outside the LAN.
RLH
Reply to: