Answered Re: FC7 adding unneccesary mailboxes in /var/mail

[Phil Meyer]

Jeroen van Meeuwen wrote:
> Timothy Murphy wrote:
>   
>> Tim wrote:
>>
>>     
>>> Tim:
>>>       
>>>>>> Has anyone else noticed that FC7's /var/mail is full of zero-byte
>>>>>> mailboxes for all users?  It includes ones for services (squid,
>>>>>> webalizer, sshd, etc.), not just human users.
>>>>>>             
>>>  
>>> Chris:
>>>       
>>>>> Not until you mentioned it.  How odd.
>>>>>           
>>> Jeroen van Meeuwen:
>>>       
>>>> It isn't really that odd at all, since all users can receive mail.
>>>> Sometimes though, they never do (some system accounts are in
>>>> /etc/aliases and forward to root, some systems never receive mail from
>>>> the outside world and are not being used to send mail locally).
>>>>         
>>> Well, odd in that this is the first distro that I've seen do that.  I'd
>>> have thought that the aliases file might have been looked at before
>>> making mailbox files.  Or that they'd be created the first time a
>>> message was sent to them.  Though I can see problems with configuring a
>>> mail client for the first time, if it directly accesses the mail spool
>>> file.
>>>
>>> I can't see it being a problem, it just seemed strange.
>>>       
>> I agree it is very strange.
>> As a matter of interest, how would I read mail addressed to tcpdump?
>>
>> Does it actually allow lunatics to send email to these virtual users?
>>
>>     
>
> One of those "lunatics" could be the cron daemon. In addition, the cron
> jobs allow a user name to be specified so that it runs the job as that user.
>
> The system however doesn't know what the user tcpdump is supposed to be
> used for. Let alone it knows that the tcpdump user is supposed to be
> used for the tcpdump program only, and that it isn't supposed to send or
> receive any mail.
>
> BTW, You can configure CREATE_MAIL_SPOOL in /etc/default/useradd to
> modify the default behaviour.
>
>   

And therein lies the answer to the original poster's question: "what 
changed?"

FC6 version of /etc/default/useradd
# useradd defaults file
GROUP=100
HOME=/home
INACTIVE=-1
EXPIRE=
SHELL=/bin/bash
SKEL=/etc/skel

F7 version of /etc/default/useradd
# useradd defaults file
GROUP=100
HOME=/home
INACTIVE=-1
EXPIRE=
SHELL=/bin/bash
SKEL=/etc/skel
CREATE_MAIL_SPOOL=yes