General IMAP functionality

Tue Nov 2 19:55:30 EST 2004

Tarjei Huse wrote:

>tir, 02,.11.2004 kl. 11.39 -0500, skrev Warrick FitzGerald:
>  
>
>>Earl R Shannon wrote:
>>
>>    
>>
>>>Hello,
>>>
>>>Comments are imbedded below.
>>>
>>>Warrick FitzGerald wrote:
>>>
>>>      
>>>
>>>>Posted this last night, but did not see it come through ... sorry 
>>>>about the re-post if you have this already.
>>>>
>>>>
>>>>============
>>>>
>>>>I’m in the process of moving an office of POP3 users to IMAP, and 
>>>>realized that that I don’t fully understand how things normally work.
>>>>
>>>>Our mail is currently hosted on an ASP basis and when a user is 
>>>>running out of disk space they receive an email saying you’re running 
>>>>out of space. I tested what happens on the IMAP side, and using 
>>>>Mozilla Thunderbird I get a message popup saying pretty much the same 
>>>>thing, but I only get this once I’ve run out of space.
>>>>
>>>>  1. Can I set Cyrus to prompt when the users’ mailbox reaches 90% 
>>>>usage?
>>>>        
>>>>
>>>    Yes. The server sends what the IMAP protocol calls an ALERT. The 
>>>client is responsible for handling it accordingly. This usually means 
>>>a POPUP. You'll need to look through the imapd.conf man page to see 
>>>how its set.
>>>
>>>      
>>>
>>>>  2. Is it possible to email an admin account when this happens? Many
>>>>     users don’t understand how to free space on the server and need
>>>>     assistance (save the comments please J ).
>>>>        
>>>>
>>>     No, Not with the native software. We've written a script that
>>>will go through and send a message to the user letting them know that 
>>>they are filling up and generate a list of those people which then gets
>>>sent to the admins.
>>>
>>>      
>>>
>>>>Now here’s the part I don’t fully understand. As far as I can gather 
>>>>you’re responsible for moving mail off the server onto you local 
>>>>machine on some regular interval. Outlook seems to have this 
>>>>“Archiving feature” that’s responsible for this, but I’m not sure if 
>>>>this is the Microsoft way of doing things, or the right way of doing 
>>>>things.
>>>>        
>>>>
>>>    Yes, the user is responsible. The IMAP protocol makes not effort
>>>to make this happen. Any ARCHIVE feature such as you mention is a 
>>>function of the client software.
>>>    
>>>
>>>      
>>>
>>>>I don’t seem to find an “Archive” feature in Thunderbird. What am I 
>>>>missing here?
>>>>        
>>>>
>>>    See above. The whole point of IMAP is to store the messages
>>>on the server. Keeping below an adminstratively imposed quota is the
>>>users responsibility. Sadly, not all users are responsible. :)
>>>
>>>      
>>>
>>>>Thanks
>>>>Warrick
>>>>
>>>>---
>>>>Cyrus Home Page: http://asg.web.cmu.edu/cyrus
>>>>Cyrus Wiki/FAQ: http://cyruswiki.andrew.cmu.edu
>>>>List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html
>>>>        
>>>>
>>>Another space issue that new IMAP users sometimes have difficulty with 
>>>is the Trash model of deleting stuff. This is a client configurable 
>>>thing so some people see it, others may not. But they move a message
>>>to Trash when they delete and don't empty the Trash. It will still use
>>>their quota.  And if they keep copies of sent messages on the Server,
>>>same deal. They use quota.
>>>
>>>Have fun.
>>>
>>>Regards,
>>>Earl Shannon
>>>      
>>>
>>Thanks Earl,
>>
>>That's what I was afraid of. Sounds to me like the people who aren't 
>>going to "get" this concept should keep using POP3 :)
>>    
>>
>
>Or embrace the concept of IMAP =) 
>
>The fact that you do not loose your mail when your disk gets lost is a
>very good reason to use IMAP - that is if you backup your server. Also,
>you can provide offsite access to mails via webmail and / or imap as
>well as provide your users with shared folders (something mine loved). 
>
>  
>
>>1. Does anyone have "best practices" that I can share with users on how 
>>they should move mail off the server when their quota is exceeded?
>>    
>>
>I'd rather buy a bigger harddrive! How many users do you have? 50, 100, 10 000?
>
>  
>
>>2. What is considered a reasonable quota (I know this is a very broad 
>>question)? When working with POP3 I would allocate users a max of 50 MB, 
>>when does a mailbox have so many messages that it puts a burden on the 
>>server?
>>    
>>
>My users have a quota of 2 gb (2x gmail) on one site and 100 mb on another (with a select few having a quota of 500 mb). 
>
>Cyrus does not have a problem with this. Reasonable quotas is something
>that IMHO is a function of your budget. It is better to keep users mail
>on the server that have them keep the mail localy.
>
>
>Tarjei
>
>  
>
>>Thanks
>>Warrick
>>
>>
>>
>>
>>---
>>Cyrus Home Page: http://asg.web.cmu.edu/cyrus
>>Cyrus Wiki/FAQ: http://cyruswiki.andrew.cmu.edu
>>List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html
>>    
>>
Great thanks that gives me a lot more confidence. I'd tested a while 
back using UW Imap and have a very bad experience. I didn't have maildir 
config setup and was reading 1GB of mail from one huge mail file and it 
took about 20 minutes to connect every time I needed to do something. I 
also could not port any of my mail and ended up trashing the lot.

If Cyrus can handle mailboxes of this size, that is certainly the 
aproach I'll take. I dont have many users that will be using IMAP so 
space should not be a huge problem.

Thanks
Warrick
---
Cyrus Home Page: http://asg.web.cmu.edu/cyrus
Cyrus Wiki/FAQ: http://cyruswiki.andrew.cmu.edu
List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html