[Evolution-users] Local delivery account

[Pete Biggs]

Please don't do Reply-All as the only version of the reply I get is the
one the gets sent to me directly and replying to that mail will break
threading for everyone.
 
On Fri, 2025-10-24 at 11:14 -0400, janos wrote:
> On Fri, 2025-10-24 at 01:15 +0100, Pete Biggs wrote:
> > 
> > If you wish the account and mail to be in a separate hierarchy on
> > the
> > sidebar, then you need an account of type "Standard Unix mbox spool
> > file".
> > 
> Very interesting. I do have a postfix mail server on my machine, and
> have /var/spool/mail/ and /var/spool/postfix/ directories on the
> machine. Everything works fine.
> 
> The /var/spool/mail/janos file is (partially listed):
> Quote
> From MAILER_DAEMON Wed Jul 13 17:52:11 2022
> Date: Wed, 13 Jul 2022 17:52:11 -0400
> From: Mail System Internal Data <MAILER-DAEMON at andraslinux>
> Subject: DON'T DELETE THIS MESSAGE -- FOLDER INTERNAL DATA
> ...
> This text is part of the internal format of your mail folder, and is
> not
> a real message.  It is created automatically by the mail system
> software.
> ...
> Unquote

Yes, those messages are common in MBOX files - as it says, it's a
message lhat is created by many mail systems- especially IMAP servers.
I suspect that in this case, since the message is from 2022 and hasn't
been updated you will be OK deleting it if you want.

> 
> OK. So just for fun in my Evo I created an account of type "Standard
> Unix mbox spool file". However, Evo could not read it and reported an
> error:
> Quote
> Error while Storing changes in folder “janosUNIX : INBOX”.
> 
> Could not lock “/var/spool/mail/janos”
> Unquote

File locking is a big issue with MBOX files particularly when multiple
programs can update them.  There are multiple paradigms for locking
that can be used - fcntl, flock, or dotlock - it really depends on what
the system is configured to use. Try using something like lslocks to
see if some other process has locked the file or look for a dot file 
in /var/spool/mail - could be something like janos.lock or .janos-lock
Ultimately, if the system is trying to use dotlocking, then it needs
write permission to the directory, which may not be the case.

> 
> OK, no problem, just my curiosity of the internal workings of mail
> system. My understanding is that originally the mail system in UNUX
> was developed with the purpose of sending messages from one user to
> another in the same UNIX machine. Later on it was adopted to
> networked UNIX machines using smtp protocol. Finally, with Internet
> and IP the domain thing completed the present email system.

That's sort of right - but SMTP wasn't always the only method of moving
mail around and early on you have to put UUCP into the mix.

> 
> My system is Gentoo Linux. It looks like the /var/spool/mail/
> directory is part of the standard distribution without any user files
> unless there is something like postfix or nullmailer installed.
> 
Yes, /var/spool/mail should exist on all Unix/Linux systems - it's not
just MTAs that use it - many system utilities assume it exists. 

And just to clarify somethings, the de facto MTA is sendmail - it is
the daddy of all MTAs in the Unix world. Postfix is a Johnny-come-
lately impostor that mimics how Sendmail works. :-)  nullmailer doesn't
deliver mail to the local system so has no use for mail spool files.

P.