how to install postfix on my 11.10 box with everything else in place?

[Rashkae]

On 11/09/2011 06:28 AM, Robert P. J. Day wrote:
> On Tue, 8 Nov 2011, Rashkae wrote:
>
>> On 11/08/2011 11:02 AM, Robert P. J. Day wrote:
>>>     openly admitting i'm not an email admin expert, i have a running
>>> 11.04 system with email running nicely -- "fetchmail" to get my mail,
>>> "alpine" as my reader and, underneath it all, postfix.
>>>
>>>     i want to finish moving everything from this current system to the
>>> new one, and the last thing left to move is the ability to get and
>>> send email.
>>>
>>>     i've copied over all of mail/, mbox, .addressbook*, .pinerc,
>>> installed fetchmail and alpine, and all that's left to do is install
>>> and configure postfix.
>>>
>>>     this *shouldn't* be hard since my .fetchmailrc and .pinerc files
>>> pretty much configure everything i need to know, i just need to drop
>>> in a basic postfix, correct?  so given my fairly basic setup, when i
>>> install postfix on the 11.10 system, which selection do i make:
>>>
>>>     No config
>>>     Internet Site
>>>     Internet with smarthost
>>>     Satellite system
>>>     Local only
>>>
>>> as i read it, i want either choice 2 or 3 but i'm not sure which.
>>> advice?
>>>
>>> rday
>>>
>> The choice really only affects how e-mail is sent out from your
>> system to other hosts on the Internet.  Most people now configure
>> their e-mail client program (alpine in your case) to connect to the
>> smtp server of their ISP, in which case, this won't matter at all.
>> You could even choose Local Only to make sure Postfix isn't trying
>> to send out anything internet side.
>    that's what i thought after reading a bit more.  currently, my
> .pinerc file has an entry of the form:
>
> smtp-server=mail.crashcourse.ca:[port]/user= ... etc etc ...
>
> and since i use only alpine for now, it would seem that that's
> everything i need.  in this case, do i even need postfix installed?  i
> ask since it's installed on my current system but it would now seem i
> never needed it in the first place.
>
>    if fetchmail is configured to know where to get my mail, and alpine
> knows where to send it, i would think i'm pretty well set, no?
>
> rday
>

You might still need local mail delivery.  You can configure a modern 
system without it, but when you start adding more classic software, 
there's a surprising amount of software that just expects sendmail to be 
there to hand off delivery of messages to local user.

Fetchmail is a good example... I don't remember if it's possible to 
configure Fetchmail to hand off delivery to some other process, but by 
default, it just uses sendmail to drop the e-mail to the right file on 
your system where alpine finds it.  (postfix in this case, working as a 
drop in sendmail replacement.  And I think both using procmail to 
actually write to the mail spool.  I don't know how this got so 
complicated for something that seems so simple.)