mail-sources versus select-methods

mail-sources versus select-methods

[Richard Riley]

Undoubtedly an incredibly naive question but why would one use
mail-sources over select-methods?

Whats the history here?  Is it just historical? Or are the select
methods simply another layer provided by Gnus to smooth over the
message.el package?

Re: mail-sources versus select-methods

[Richard Riley]

Leonidas Tsampros <ltsampros@upnet.gr> writes:

> Richard Riley <rileyrg@googlemail.com> writes:
>> Undoubtedly an incredibly naive question but why would one use
>> mail-sources over select-methods?
>>
>
> I think I have the same question my self. However, mail-sources is just
> a 'digest' method.

What does digest mean in this instance? It can be all sorts including
pop3 etc.

>
> Quoting the docs:
>
> mail-sources is a variable defined in `mail-source.el'.
> Its value is ((directory :path "~/Mail" :suffix ""))
>

Thats  not the docs but rather its current value.

See

(gnus) Mail Source Specifiers


in the gnus manual for more info. 

But you probably meant that ;)

> What I do not understand is which mail backend (if multiple are defined)
> is going to consume these mails ?

Me neither.

My setting is

,----
| mail-sources is a variable defined in `mail-source.el'.
| Its value is 
| ((file :path "/var/spool/mail/shamrock"))
`----

I access it via nnml :

   (add-to-list 'gnus-secondary-select-methods
                '(nnml "spool"
                         ))
   

You would have no idea how long it took me to get to that ;)

I still dont really really understand the connection. Gnus does so much
under the cover and makes some really clever guesses at what you want.
I think because nnml is a mail backend, it just assumes its fed from
mail-sources. A reasonable enough assumption. Which then begs your question.

>
>> Whats the history here?  Is it just historical? Or are the select
>> methods simply another layer provided by Gnus to smooth over the
>> message.el package?
>
> I think message.el is just the glue part where mails are composed and
> sent out. I'm not source it has anything to do with mail-sources.
>
> Select methods on the other hand is the backends from which you READ
> email. (that's how I understand it, please someone correct me if I'm
> wrong)

and other stuff such as nntp or google "pseudo" groups (which doesnt
work in HEAD btw (G W)).

Re: mail-sources versus select-methods

[Leonidas Tsampros]

Richard Riley <rileyrg@googlemail.com> writes:
> Undoubtedly an incredibly naive question but why would one use
> mail-sources over select-methods?
>

I think I have the same question my self. However, mail-sources is just
a 'digest' method.

Quoting the docs:

mail-sources is a variable defined in `mail-source.el'.
Its value is ((directory :path "~/Mail" :suffix ""))

What I do not understand is which mail backend (if multiple are defined)
is going to consume these mails ?

> Whats the history here?  Is it just historical? Or are the select
> methods simply another layer provided by Gnus to smooth over the
> message.el package?

I think message.el is just the glue part where mails are composed and
sent out. I'm not source it has anything to do with mail-sources.

Select methods on the other hand is the backends from which you READ
email. (that's how I understand it, please someone correct me if I'm
wrong)

Re: mail-sources versus select-methods

[Dave Goldberg]

> Leonidas Tsampros <ltsampros@upnet.gr> writes:
>> Richard Riley <rileyrg@googlemail.com> writes:
>>> Undoubtedly an incredibly naive question but why would one use
>>> mail-sources over select-methods?
>>> 

One doesn't.  They are two complementary things.

A backend is the entity from where Gnus reads email.  You pick your backends through select methods.  Some back ends work by communicating directly with a server, think nnimap, nntp.  Others, such as nnml or nnfolder, look for mail on the local system.  In most cases, these backends are just directories of files.  The population of those directories can be done in a myriad of ways.  If Gnus is going to be doing the populating, the mail-sources specification is how you tell Gnus to do it.

-- 
Dave Goldberg
david.goldberg6@verizon.net

Re: mail-sources versus select-methods

[Richard Riley]

david.goldberg6@verizon.net (Dave Goldberg) writes:

>> Leonidas Tsampros <ltsampros@upnet.gr> writes:
>>> Richard Riley <rileyrg@googlemail.com> writes:
>>>> Undoubtedly an incredibly naive question but why would one use
>>>> mail-sources over select-methods?
>>>> 
>
> One doesn't.  They are two complementary things.
>
Hi,

But one can. And I'm not clear what is best.

One does not have to set up mail-sources. It can all be done in
secondary methods - e.g see the nnimap select-method in the manual for
gmail:-


     (setq gnus-select-method
           '(nnimap "imap.gmail.com"))


> A backend is the entity from where Gnus reads email.  You pick your backends
> through select methods.  Some back ends work by communicating directly with a
> server, think nnimap, nntp.  Others, such as nnml or nnfolder, look for mail on
> the local system.  In most cases, these backends are just directories of files.
> The population of those directories can be done in a myriad of ways.  If Gnus is
> going to be doing the populating, the mail-sources specification is how you tell
> Gnus to do it.

Or via the select method/secondary select method as above. Or am I
seriously confused here? 

thanks

r.

Re: mail-sources versus select-methods

[Dave Goldberg]

> david.goldberg6@verizon.net (Dave Goldberg) writes:
>>> Leonidas Tsampros <ltsampros@upnet.gr> writes:
>>>> Richard Riley <rileyrg@googlemail.com> writes:
>>>>> Undoubtedly an incredibly naive question but why would one use
>>>>> mail-sources over select-methods?
>>>>> 
>> 
>> One doesn't.  They are two complementary things.
>> 
> Hi,

> But one can. And I'm not clear what is best.

Apples and oranges.  The two are complementary - there's no competition here.

> One does not have to set up mail-sources. It can all be done in
> secondary methods - e.g see the nnimap select-method in the manual for
> gmail:-

That's right, you don't need to set up mail-sources if you're not sucking mail into a local back end.  If you are, then you need to tell Gnus from where to get it.  That's the mail-source.  The select method in that case would be the actual back end into which you're putting the mail.


>      (setq gnus-select-method
>            '(nnimap "imap.gmail.com"))

Right so here you're talking IMAP, over the network, and interacting directly with the server.  You don't need a mail-source because you're not pulling that mail into some local folder.  If you did you might use nnml or similar as the back end (select method).


-- 
Dave Goldberg
david.goldberg6@verizon.net

Re: mail-sources versus select-methods

[Richard Riley]

david.goldberg6@verizon.net (Dave Goldberg) writes:

>> david.goldberg6@verizon.net (Dave Goldberg) writes:
>>>> Leonidas Tsampros <ltsampros@upnet.gr> writes:
>>>>> Richard Riley <rileyrg@googlemail.com> writes:
>>>>>> Undoubtedly an incredibly naive question but why would one use
>>>>>> mail-sources over select-methods?
>>>>>> 
>>> 
>>> One doesn't.  They are two complementary things.
>>> 
>> Hi,
>
>> But one can. And I'm not clear what is best.
>
> Apples and oranges.  The two are complementary - there's no
> competition here.

But there is. You can achieve  the same thing using both. My Q is what s
best and why.

>
>> One does not have to set up mail-sources. It can all be done in
>> secondary methods - e.g see the nnimap select-method in the manual for
>> gmail:-
>
> That's right, you don't need to set up mail-sources if you're not sucking mail
> into a local back end.  If you are, then you need to tell Gnus from
> where to get

And you dont need to if you are either.

> it.  That's the mail-source.  The select method in that case would be the actual
> back end into which you're putting the mail.
>
>>      (setq gnus-select-method
>>            '(nnimap "imap.gmail.com"))
>
> Right so here you're talking IMAP, over the network, and interacting directly
> with the server.  You don't need a mail-source because you're not pulling that
> mail into some local folder.  If you did you might use nnml or similar as the
> back end (select method).

You can set up a mail-source with imap too. And a secondary select with
local backend too. I dont see where I ever "need" a mail-source which is
the core of my query really. Up until recently I never set mail-source
and am only doing so now because of issues I had with nnml as a
secondary select.
 

Re: mail-sources versus select-methods

[Dave Goldberg]

>> Apples and oranges.  The two are complementary - there's no
>> competition here.

> But there is. You can achieve  the same thing using both. My Q is what s
> best and why.

Really?  How can you use a mail source without a select method?

I submit by my previous statement.  A select method (back end) is how you tell Gnus to read mail/news.  A mail source is how you tell Gnus to populate the back end if Gnus is going to be responsible for that.  It need not be.

-- 
Dave Goldberg
david.goldberg6@verizon.net

Re: mail-sources versus select-methods

[Richard Riley]

david.goldberg6@verizon.net (Dave Goldberg) writes:

>>> Apples and oranges.  The two are complementary - there's no
>>> competition here.
>
>> But there is. You can achieve  the same thing using both. My Q is what s
>> best and why.

>
> Really?  How can you use a mail source without a select method?

I never suggested you can. I said you can read mail and news without
setting mail-sources. Local and remote afaik.

>
> I submit by my previous statement.  A select method (back end) is how you tell
> Gnus to read mail/news.  A mail source is how you tell Gnus to populate the back
> end if Gnus is going to be responsible for that.  It need not be.

My point is that you dont need to set mail-sources. It seems that it can
all be done in the select methods - my query is based on this point
only. Or can it?  I pointed out before that the mail-sources can include
imap, pop3 etc : all of which can also be put into the select method and
thus imap/pop3 are "mail sources" or "sources of mail". As I mentioned
before I have used gnus for a long time now and only recently user
mail-sources for the local system mail - I had been using only secondary
selects before for maildir, imap and pop3 access all of which are "mail
sources". Is this just a silly vocab issue I have I wonder?

Re: mail-sources versus select-methods

[Dave Goldberg]

> david.goldberg6@verizon.net (Dave Goldberg) writes:
>>>> Apples and oranges.  The two are complementary - there's no
>>>> competition here.
>> 
>>> But there is. You can achieve  the same thing using both. My Q is what s
>>> best and why.

>> 
>> Really?  How can you use a mail source without a select method?

> I never suggested you can. I said you can read mail and news without
> setting mail-sources. Local and remote afaik.

OK, so we're in violent agreement :-)

> My point is that you dont need to set mail-sources. It seems that it can

Right, that's exactly what I said.  But now I understand what you're referring to.  Yes, it is possible to specify the mail-source equivalent directly in the select method.  I expect that's something that got added on over time.  I have mail-sources set at home for my POP server, but I've been set up that way since September Gnus (and maybe even earlier though I am pretty sure I was still using mh-e back in those days).

-- 
Dave Goldberg
david.goldberg6@verizon.net

Re: mail-sources versus select-methods

[Richard Riley]

david.goldberg6@verizon.net (Dave Goldberg) writes:

>> david.goldberg6@verizon.net (Dave Goldberg) writes:
>>>>> Apples and oranges.  The two are complementary - there's no
>>>>> competition here.
>>> 
>>>> But there is. You can achieve  the same thing using both. My Q is what s
>>>> best and why.
>
>>> 
>>> Really?  How can you use a mail source without a select method?
>
>> I never suggested you can. I said you can read mail and news without
>> setting mail-sources. Local and remote afaik.
>
> OK, so we're in violent agreement :-)
>

Great ;)

>> My point is that you dont need to set mail-sources. It seems that it can
>
> Right, that's exactly what I said.  But now I understand what you're referring
> to.  Yes, it is possible to specify the mail-source equivalent directly in the
> select method.  I expect that's something that got added on over time.  I have

OK, I thought when you said this

,----
| david.goldberg6@verizon.net (Dave Goldberg) writes:
| 
| >> Leonidas Tsampros <ltsampros@upnet.gr> writes:
| >>> Richard Riley <rileyrg@googlemail.com> writes:
| >>>> Undoubtedly an incredibly naive question but why would one use
| >>>> mail-sources over select-methods?
| >>>> 
| >
| > ** One doesn't.  They are two complementary things. **
| >
| (ME) Hi,
| 
| But one can. And I'm not clear what is best.
| 
`----

you were in violent disagreement.

> mail-sources set at home for my POP server, but I've been set up that way since
> September Gnus (and maybe even earlier though I am pretty sure I was still using
> mh-e back in those days).

So I guess my original Q stands.

Re: mail-sources versus select-methods

[Dave Goldberg]

>> mail-sources set at home for my POP server, but I've been set up that way since
>> September Gnus (and maybe even earlier though I am pretty sure I was still using
>> mh-e back in those days).

> So I guess my original Q stands.

Take a look at nnmail.el, particularly nnmail-get-new-mail-1.  Ultimately whether you specify your mail source with mail-sources or a group specifier, it all ends up in the same code.

Although it wasn't my original understanding of the question, I still say it makes no difference, other than style.

-- 
Dave Goldberg
david.goldberg6@verizon.net