>>>>> "Emilio" == Emilio Augusto Lazo Zaia <emiliolazoz...@gmail.com> writes:
> Hello John! Thanks for your answer. You're welcome, but I'm not sure I'm going to be able to help here. I suspect this is a client issue, just like I hate how the Apple Mail client marks messages SEEN for no reason at all because it does "SELECT INBOX" vs "EXAMINE INBOX". > On 12/9/22 12:30, John Stoffel wrote: > I have a setup on which dovecot is the server in a domain on which > mailboxes are >20GB, some of > them are 150GB or more. > It looks like you're using Maildir format? In any case, please post > more details of your configuration. > Sure. It is a simple setup, with Maildir. > # doveconf -N > auth_debug = no > auth_mechanisms = plain login > auth_verbose = no > debug_log_path = /var/log/syslog/mail.debug > disable_plaintext_auth = no > login_greeting = Hermes. > mail_debug = yes > mail_index_rewrite_max_log_bytes = 1 M > mail_location = maildir:~/Maildir > namespace inbox { > inbox = yes > location = > mailbox Drafts { > special_use = \Drafts > } > mailbox Junk { > special_use = \Junk > } > mailbox Sent { > special_use = \Sent > } > mailbox "Sent Messages" { > special_use = \Sent > } > mailbox Trash { > special_use = \Trash > } > prefix = > } > passdb { > driver = pam > name = > } > protocols = " imap" > service auth { > unix_listener auth-client { > group = Debian-exim > mode = 0660 > user = Debian-exim > } > } > service imap { > vsz_limit = 2 G > } > ssl = yes > ssl_cert = </etc/dovecot/dovecot-cert.pem > ssl_client_ca_dir = /etc/ssl/certs > ssl_dh = # hidden, use -P to show it > ssl_key = # hidden, use -P to show it > userdb { > driver = passwd > name = > } > verbose_proctitle = yes > protocol imap { > mail_max_userip_connections = 20 > } > When reconfiguring _some_ mailboxes with Outlook 365 (configuring a > previously used mailbox on a > new PC), the process takes too long even if mail visibility on > Outlook is 3 months. > So the outlook client can't download and parse the number of messages > on there without breaking? How many messages are there? It's > probably not the size of the mailbox, but the number of messages. > 50K mails on some folders... total 5.5M on the whole server. I did discover > which was the problem > but I don't have a solution. Yeah, that's alot. You might need to push your clients to start putting more emails into sub-folders, maybe split up by year say, so they don't have quite so many emails sitting around. > Inspecting at INBOX cur directory I did note that the 'ls' command > shows the last file listed is a > file from year 2020, 2019 or whatever not being the last received > mail; that means the > alphabetical ordering of 'ls' is showing past years after the last > received mail, i.e. dovecot > changed the epoch in filename. This only happens with Outlook. > Following is an excerpt of ls: > Sure, 'ls -l' doesn't do any sorting, it just reads the directory > information as returned from the disk and show you the results. If > you want it by time, you need to do: > ls -ltr > to have the newest files be at the end. But how 'ls' sees the > directry entries doen't matter to dovecot. > Newest files are at the end; 'ls' without '-U' or '--sort=none' lists files > ordered > alphabetically, so the last entry would be the last mail placed on the folder > because the epoch > time is part of the filename in Maildir structure... > -rw-r--r-- 1 coord.ventas ventas 544765 sep 9 10:57 > 1662769412.M329925P1259441.xyz.com,S= > 544765,W=552045:2, > -rw-r--r-- 1 coord.ventas ventas 163491 sep 5 12:14 > 1662769412.M74257P1259441.xyz.com,S= > 163491,W=165846:2,S > -rw-r--r-- 1 coord.ventas ventas 3043536 sep 9 12:02 > 1662769412.M777084P1259441.xyz.com,S= > 3043536,W=3083246:2, > -rw-r--r-- 1 coord.ventas ventas 161002 feb 27 2020 > 1662874173.M608062P1282222.xyz.com,S= > 161002,W=163373:2,S > -rw-r--r-- 1 coord.ventas ventas 2230491 feb 27 2020 > 1662874176.M281294P1282222.xyz.com,S= > 2230491,W=2259506:2,S > -rw-r--r-- 1 coord.ventas ventas 167925 feb 27 2020 > 1662874176.M741229P1282222.xyz.com,S= > 167925,W=170373:2,S > The process of renaming files is continuous until all folder was > reread and renamed every file on it. If I issue 'lsof' (with grep) I > see the file that is being renamed passing through tmp/ directory > and after that, the file is placed under new/ directory (I guess) > and Outlook sees a new email to sync, making the sync process too > long... mails that have been synced are resynced... > Wait what? Can you explain exactly what you're doing here? Why would > O365 client be renaming the file > Ok, I disabled TLS options and inspected the traffic with tcpdump. I did note > unnecesary STORE, > EXPUNGE and APPEND operations on previously synced folder. I guess the whole > mailbox is analyzed > (from the local cache on .pst file) and O365 tags as SPAM a large number of > innocent emails > (including local mails from the same domain which does not travel through > internet to reach the > destination). So this is really a client issue. You might need to ask around on the Microsoft site to see if there are any settings you can change when it's accessing a server using IMAP. Also, look in the dovecot archives. > Also I'm using port 144 instead of 143 to bypass GData antivirus > SPAM checks. Anyway I completely disabled GData antivirus and none > of its services remains running on these workstations; also starting > Outlook with safe mode exhibits this behavior, so I don't know which > feature is this on O365 that rescan all stored emails but it is > beyond the scope of this list because there is no feature on dovecot > that can be enabled to workaround this. I guess this is a bug on > O365. Yup, sorry! > All mails are retransmitted to the server with the subject modified (tagging > them as SPAM or SPAM > suspected) and obviously dovecot stores them with a new epoch timestamp on > filename and that's why > I have mails with older timestamp but with recent epoch time on filename... > Take a look at the timestamp on filenames: 1662769412 corresponds to > "Fri Sep 9 20:23:32 -04 2022" and 1662874176 corresponds to Sun Sep > 11 01:29:36 -04 2022 but mails were neither sent nor received on > that dates. > What is Outlook requesting imap server to do and how to avoid this? > What is the outlook client version? What are your connection > settings? Have you looked in the logs on the dovecot server side to > see what they say? > Outlook 365 is version 16.15601.20148 compilation 2208 on one workstation > that exhibits the issue > and this same version on another PC on which this issue is not present... > What working clients are your users using today? Are they working > properly with older clients? > Basically I'm the mail server administrator not the sysadmin on the network. > All users prefer > working with O365. I've installed Thunderbird on every PC but users refuses > to use it in favor of > using Outlook, unfortunately. > Basically, you have to assume we know nothing and explain your setup > and configuration to us like we're idiots who don't know anything. > Spell out all the details please. :-) > Yes, I'm sorry. I hope with this mail I've clarified the scenario. > Thanks again! > Emilio