Re: [cpx] Limit on mailbox size using CPX

[Rus Berrett <rberrett@xxxxxxxxx>]

On Fri, Jun 02, 2006 at 01:27:57PM +0530, Quentin Desouza wrote:
>
> Subject: [cpx] Limit on mailbox size using  CPX
>
> One of my clients complained that they were getting 0 mails in the inbox 
> although there were many mails there.
> the only way to see the mails was to go to the inbox via the folder list 
> button.
> The Verio tech gave me the following explanation why this happens.
> If this was so how does it not time out when going via the folder list to 
> inbox?
> Explanation from tech support IDS-8185203 :-
> "The problem with displaying the inbox, is that the inbox to big. CPX or 
> any other e-mail program will have a problem reading an inbox that is over 
> 20 mb. The inbox on the server is just a text file. Every time the inbox is 
> opened the file has to sorted into the different e-mails, this can take a 
> while and it will fail. The files need to kept under 20 mb, ideally under 
> 10 MB. This should help to resolve the issue. The user needs to remove most 
> of the e-mail."
> 
> I wonder how google and all the rest have no problem working with inboxes 
> greater than 2GB !!
> My client is asking me why I have given him 100 MB if I am going to impose 
> a 20 MB limit on his inbox.
> 
> Quentin.

Quentin,

I now have this in my queue to look at.

There is no limit to the mailbox size per se.  If imapd can parse it,
then CPX should be able to read/display it just fine.  There are some
timeout limits; both on the Apache side (which is configurable in your 
httpd.conf), and on the vsap side (which is 60 seconds... and may be 
configurable... not sure).  And there are some memory limits (per your 
server type).  But a 20MB mail folder with several hundred e-mail
messages should present no problems from the CPX point-of-view.

In fact 20MB is on the low end of what I have successfully tested.  I
have created file folders approached 1 GB in size and was able to load
them using CPX's webmail.  My presumption is that it wasn't a problem
with the file size per se, but rather the amount of messages that were
contained in the mailbox.  This is because the mailbox parser must store
a certain amount of information for each message in order to sort the
messages and then display the ones that the user is interested in... the
more messages that are in the mailbox, the more memory is required in
order to load and sort the messages in the mailbox.  Furthermore, it
takes the CPU much longer to sort tens of thousands of e-mail messages
than it does just a few hundred.  If the memory limits are reached
before the mailbox is fully parsed or if a timeout event is triggered 
before the loaded messags can be successfully sorted, then errors can 
occur as a result.

If you still have a copy of the mailbox that is causing problems, then
I would be very pleased to take a look at it.  Please e-mail me
off-list.

cheers.

--rus.


========================================================================
Rus Berrett                                                    NTT/Verio
                 See Perl. See Perl Run. Run Perl, Run!

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