Re: Postfix and quota clarification
hi! On Tue, Nov 25, 2008 at 4:18 AM, Rocco Scappatura [EMAIL PROTECTED] wrote: On Mon, Nov 24, 2008 at 4:49 AM, mouss [EMAIL PROTECTED] wrote: Jose Ildefonso Camargo Tolosa a écrit : However, Postfix supports access maps that can reject mail for over-quota users, if you are willing to periodically add up all the mail each user has. I have been using filesystem quotas for this purpose, and it works just fine. Off course, I have a dedicated filesystem for mail storage. The problem is that this is detected at delivery time, which will cause backscatter if it happens too often and your filter misses a lot of spam. if this doesn't happen often, then yes, it's the easy way. otherwise, an access check as suggested by Wietse may be necessary. True, that's why I try to implement many quota warning systems, so the user knows that he/she have to clean their mailbox, also, there is a side-effect to the fs quota: it is pretty much likely that the imap server (dovecot) fail to access the user mailbox once the hard limit is over (unless you fix it, but I didn't), and they just call support, and then one tells them to clean up the mailbox asap, and just reenable the access (by deleting a couple of dovecot's files, and extending their quota for a while). Well, I also try to have a good spam filter (ASSP). 2- there is no safe quota support in any MTA. most quota implementations will send a bounce, which may resultin backscatter true. but quotas are necessary: the more disk space the users have, the more garbage they store. but this doesn't require checking quota in real time or at delivery time. populating an access list (periodically or opportunistically) should be enough. maybe, but can also prove to be slow, and even more when you have thousands of users. I think that... maybe... using soft-quotas (as a counter) and having unlimited hard-quota and grace periods could have a similar effect, and can be faster (I don't know if this actually works, I hasn't tried) Infact, this is exactly the problem that I have. I'm using Postfix as post-office platform too. And I need to check disk usage. First time I ve patched with VDA patch. Then I have upgraded postfix and I have no more appliad the relative patch. Indeed I read that is not good to use VDA patch so I have believed that that there was a native support for quota by Postfix. Anyway I share the fact that MTA has not to face quota issues, as mouss pointed out in a previous email. But I have to check quota exactly for the same needs that you have exposed. Have you a pratical alternative to VDA patch to suggest me? Well I don't know, I just installed Postfix, and configured fs quota (Debian GNU/Linux), and it just worked. I also use Dovecot, and configured the quota plug-in and used the fs backend, just to let the webmail app get quota info and show a nice quota bar. I also run warnquota from a cron job every day at 08:00, to send a warning mail to overquota users (over soft quota, off course).
RE: Postfix and quota clarification
On Mon, Nov 24, 2008 at 4:49 AM, mouss [EMAIL PROTECTED] wrote: Jose Ildefonso Camargo Tolosa a écrit : However, Postfix supports access maps that can reject mail for over-quota users, if you are willing to periodically add up all the mail each user has. I have been using filesystem quotas for this purpose, and it works just fine. Off course, I have a dedicated filesystem for mail storage. The problem is that this is detected at delivery time, which will cause backscatter if it happens too often and your filter misses a lot of spam. if this doesn't happen often, then yes, it's the easy way. otherwise, an access check as suggested by Wietse may be necessary. True, that's why I try to implement many quota warning systems, so the user knows that he/she have to clean their mailbox, also, there is a side-effect to the fs quota: it is pretty much likely that the imap server (dovecot) fail to access the user mailbox once the hard limit is over (unless you fix it, but I didn't), and they just call support, and then one tells them to clean up the mailbox asap, and just reenable the access (by deleting a couple of dovecot's files, and extending their quota for a while). Well, I also try to have a good spam filter (ASSP). 2- there is no safe quota support in any MTA. most quota implementations will send a bounce, which may resultin backscatter true. but quotas are necessary: the more disk space the users have, the more garbage they store. but this doesn't require checking quota in real time or at delivery time. populating an access list (periodically or opportunistically) should be enough. maybe, but can also prove to be slow, and even more when you have thousands of users. I think that... maybe... using soft-quotas (as a counter) and having unlimited hard-quota and grace periods could have a similar effect, and can be faster (I don't know if this actually works, I hasn't tried) Infact, this is exactly the problem that I have. I'm using Postfix as post-office platform too. And I need to check disk usage. First time I ve patched with VDA patch. Then I have upgraded postfix and I have no more appliad the relative patch. Indeed I read that is not good to use VDA patch so I have believed that that there was a native support for quota by Postfix. Anyway I share the fact that MTA has not to face quota issues, as mouss pointed out in a previous email. But I have to check quota exactly for the same needs that you have exposed. Have you a pratical alternative to VDA patch to suggest me? 3- if you can queue mail, you can deliver it ;-p As I just have pointed out, I'm using as Post office. 4- disks don't cost too much now. true, but when you have 10k users, the cost of each not so expensive hard drive starts to add, and not only that, in a public organization you can have wait-times of around 6 months just to get a hard drive. Oh, and don't forget: you have plug these hard drives somewhere: every server has they hard drives limit, and you could take a PC and lots of SATA controllers, and build a nice low-cost NAS-like thing, but a few people qualify this as unreliable, they need to spend lots of money on IBM or HP storage systems, and because of the cost, they just don't buy them, and thus: we have a limited amount of disk space :( . Agreed. 5- if your users abuse mail, destroy their heads, not ours. I don't think my boss let me do that, jejejeje :D you must make it look like an accident :) ... jejejejeje :D Very smart! I will try.. ;-)
Re: Postfix and quota clarification
Jose Ildefonso Camargo Tolosa a écrit : However, Postfix supports access maps that can reject mail for over-quota users, if you are willing to periodically add up all the mail each user has. I have been using filesystem quotas for this purpose, and it works just fine. Off course, I have a dedicated filesystem for mail storage. The problem is that this is detected at delivery time, which will cause backscatter if it happens too often and your filter misses a lot of spam. if this doesn't happen often, then yes, it's the easy way. otherwise, an access check as suggested by Wietse may be necessary. 2- there is no safe quota support in any MTA. most quota implementations will send a bounce, which may resultin backscatter true. but quotas are necessary: the more disk space the users have, the more garbage they store. but this doesn't require checking quota in real time or at delivery time. populating an access list (periodically or opportunistically) should be enough. 3- if you can queue mail, you can deliver it ;-p 4- disks don't cost too much now. true, but when you have 10k users, the cost of each not so expensive hard drive starts to add, and not only that, in a public organization you can have wait-times of around 6 months just to get a hard drive. Oh, and don't forget: you have plug these hard drives somewhere: every server has they hard drives limit, and you could take a PC and lots of SATA controllers, and build a nice low-cost NAS-like thing, but a few people qualify this as unreliable, they need to spend lots of money on IBM or HP storage systems, and because of the cost, they just don't buy them, and thus: we have a limited amount of disk space :( . Agreed. 5- if your users abuse mail, destroy their heads, not ours. I don't think my boss let me do that, jejejeje :D you must make it look like an accident :) c-ya! Ildefonso.
Re: Postfix and quota clarification
On Mon, Nov 24, 2008 at 4:49 AM, mouss [EMAIL PROTECTED] wrote: Jose Ildefonso Camargo Tolosa a écrit : However, Postfix supports access maps that can reject mail for over-quota users, if you are willing to periodically add up all the mail each user has. I have been using filesystem quotas for this purpose, and it works just fine. Off course, I have a dedicated filesystem for mail storage. The problem is that this is detected at delivery time, which will cause backscatter if it happens too often and your filter misses a lot of spam. if this doesn't happen often, then yes, it's the easy way. otherwise, an access check as suggested by Wietse may be necessary. True, that's why I try to implement many quota warning systems, so the user knows that he/she have to clean their mailbox, also, there is a side-effect to the fs quota: it is pretty much likely that the imap server (dovecot) fail to access the user mailbox once the hard limit is over (unless you fix it, but I didn't), and they just call support, and then one tells them to clean up the mailbox asap, and just reenable the access (by deleting a couple of dovecot's files, and extending their quota for a while). Well, I also try to have a good spam filter (ASSP). 2- there is no safe quota support in any MTA. most quota implementations will send a bounce, which may resultin backscatter true. but quotas are necessary: the more disk space the users have, the more garbage they store. but this doesn't require checking quota in real time or at delivery time. populating an access list (periodically or opportunistically) should be enough. maybe, but can also prove to be slow, and even more when you have thousands of users. I think that... maybe... using soft-quotas (as a counter) and having unlimited hard-quota and grace periods could have a similar effect, and can be faster (I don't know if this actually works, I hasn't tried) 3- if you can queue mail, you can deliver it ;-p 4- disks don't cost too much now. true, but when you have 10k users, the cost of each not so expensive hard drive starts to add, and not only that, in a public organization you can have wait-times of around 6 months just to get a hard drive. Oh, and don't forget: you have plug these hard drives somewhere: every server has they hard drives limit, and you could take a PC and lots of SATA controllers, and build a nice low-cost NAS-like thing, but a few people qualify this as unreliable, they need to spend lots of money on IBM or HP storage systems, and because of the cost, they just don't buy them, and thus: we have a limited amount of disk space :( . Agreed. 5- if your users abuse mail, destroy their heads, not ours. I don't think my boss let me do that, jejejeje :D you must make it look like an accident :) ... jejejejeje :D c-ya! Ildefonso.
Re: Postfix and quota clarification
Hi! On Sat, Nov 22, 2008 at 9:53 PM, Wietse Venema [EMAIL PROTECTED] wrote: mouss: Rocco Scappatura a ?crit : Hello, I have a post-office platform based on Postfix-2.5.2+Courier-IMAP-4.0.1-Courier-authlib-0.53+MySQL-5.0.33. Can someone give some hint on how enable (and verify that works) quota on mailboxes? 1- there is no quota support in postfix. However, Postfix supports access maps that can reject mail for over-quota users, if you are willing to periodically add up all the mail each user has. I have been using filesystem quotas for this purpose, and it works just fine. Off course, I have a dedicated filesystem for mail storage. Wietse 2- there is no safe quota support in any MTA. most quota implementations will send a bounce, which may resultin backscatter true. but quotas are necessary: the more disk space the users have, the more garbage they store. 3- if you can queue mail, you can deliver it ;-p 4- disks don't cost too much now. true, but when you have 10k users, the cost of each not so expensive hard drive starts to add, and not only that, in a public organization you can have wait-times of around 6 months just to get a hard drive. Oh, and don't forget: you have plug these hard drives somewhere: every server has they hard drives limit, and you could take a PC and lots of SATA controllers, and build a nice low-cost NAS-like thing, but a few people qualify this as unreliable, they need to spend lots of money on IBM or HP storage systems, and because of the cost, they just don't buy them, and thus: we have a limited amount of disk space :( . 5- if your users abuse mail, destroy their heads, not ours. I don't think my boss let me do that, jejejeje :D c-ya! Ildefonso.
Postfix and quota clarification
Hello, I have a post-office platform based on Postfix-2.5.2+Courier-IMAP-4.0.1-Courier-authlib-0.53+MySQL-5.0.33. Can someone give some hint on how enable (and verify that works) quota on mailboxes? Thanks, rocsca
Re: Postfix and quota clarification
Rocco Scappatura a écrit : Hello, I have a post-office platform based on Postfix-2.5.2+Courier-IMAP-4.0.1-Courier-authlib-0.53+MySQL-5.0.33. Can someone give some hint on how enable (and verify that works) quota on mailboxes? 1- there is no quota support in postfix. 2- there is no safe quota support in any MTA. most quota implementations will send a bounce, which may resultin backscatter 3- if you can queue mail, you can deliver it ;-p 4- disks don't cost too much now. 5- if your users abuse mail, destroy their heads, not ours.
