- dovecot - dovecot.org

[Dovecot] Throttle New Connections?
by Joe Allesi -X (joallesi - Coyote Creek Consulting at Cisco) 21 Nov '07

21 Nov '07

All, Is anyone using iptables (recent module), or any other alternatives, to throttle the number of new imap or pop connections per minute? We have some applications that like to login every second to pull mail using imap, so we'd like to protect the entire dovecot server from these applications. We've already made the change over to high-perf mode, but we still need some type of denial of service protection. Any real-world data would be appreciated. Thanks!

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[Dovecot] Just getting started
by Randall Donaldson 20 Nov '07

20 Nov '07

This is my first attempt at creating a mail server. I'm running postfix and dovecot on Fedora 7. So far the process has been very enlightening. I currently have the server able to send and receive messages for a domain from the server machine itself. In addition, I can SMTP from any client set up on the LAN by logging in. However, I cannot retrieve messages from remote clients on the LAN. Thunderbird reads "Connected to" {servername} across the bottom, then times out. I tried to telnet to port 110 on the server, and I no response, just hangs. Not sure where the problem lies. Thanks for any assistance. here's the output of dovecot -n: # 1.0.7: /etc/dovecot.conf login_dir: /var/run/dovecot/login login_executable(default): /usr/libexec/dovecot/imap-login login_executable(imap): /usr/libexec/dovecot/imap-login login_executable(pop3): /usr/libexec/dovecot/pop3-login mail_executable(default): /usr/libexec/dovecot/imap mail_executable(imap): /usr/libexec/dovecot/imap mail_executable(pop3): /usr/libexec/dovecot/pop3 mail_plugin_dir(default): /usr/lib/dovecot/imap mail_plugin_dir(imap): /usr/lib/dovecot/imap mail_plugin_dir(pop3): /usr/lib/dovecot/pop3 auth default: passdb: driver: pam userdb: driver: passwd Randall Donaldson Information Technology Stolze Printing

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[Dovecot] virtual user login
by Paul A 20 Nov '07

20 Nov '07

Hi, I have server with multiple virtual domains and this server also accepts mail for the local domain. I'm using postfix and have the following setup for a virtual sales(a)domain.com mapped to custsales@localhost I was wondering if there is a way to login with the virtual email address, for example sales(a)domain.com? I would also like to still be able to login with the local user as well. TIA, P

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[Dovecot] IMAP Proxy and Namespaces
by it-dovecot＠ml.epigenomics.com 20 Nov '07

20 Nov '07

Hi! Is it possible to combine these two features of dovecot, i.e. to have a specific namespace that proxies to another IMAP server? Greetings -- Robert Sander

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[Dovecot] How to write plugin
by Eugene Prokopiev 20 Nov '07

20 Nov '07

Hi, Where can I find documentation for plugin writers? Now I see mail-log-plugin source, but I can't understand how entry points (functions mail-log-plugin-init and mail-log-plugin-deinit) are defined to execute some actions on load/unload/copy messages. Can anybody comments this?

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[Dovecot] Mailbox is in inconsistent state
by Nikolay Shopik 20 Nov '07

20 Nov '07

I have few such messages should I aware about them or just ignore? Disconnected: Mailbox is in inconsistent state, please relogin.

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[Dovecot] Helping OS's page cache
by Timo Sirainen 20 Nov '07

20 Nov '07

http://dovecot.org/patches/1.1/fadvise.diff http://dovecot.org/patches/1.0/fadvise.diff These patches try to tell kernel when mail files are wanted to be read and when they're wanted out of memory, so the memory could be used for more important things such as index files. I'd like to hear if someone sees any actual changes (for better or worse) in the system load because of this. I'm not sure if I should add this to v1.1 and if it should be enabled by default.

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[Dovecot] src/lib/Makefile.am: a trivial ``$(srcdir)'' patch
by Ivan Shmakov 20 Nov '07

20 Nov '07

May I suggest the following trivial patch? diff -r ff9e591a2aa5 src/lib/Makefile.am --- a/src/lib/Makefile.am Sun Nov 18 21:44:22 2007 +0200 +++ b/src/lib/Makefile.am Tue Nov 20 00:29:04 2007 +0600 @@ -4,9 +4,9 @@ BUILT_SOURCES = unicodemap.c EXTRA_DIST = unicodemap.c unicodemap.pl -unicodemap.c: +$(srcdir)/unicodemap.c: test -f UnicodeData.txt || wget http://www.unicode.org/Public/UNIDATA/UnicodeData.txt - perl unicodemap.pl < UnicodeData.txt > $@ + perl $(srcdir)/unicodemap.pl < UnicodeData.txt > $@ liblib_a_SOURCES = \ backtrace-string.c \

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[Dovecot] imap process consuming 100% CPU (Dovecot 1.0.3)
by Robert Tomanek 20 Nov '07

20 Nov '07

Hi, I have yet another problem with Dovecot: sometimes (rarely, maybe once every few days) one of the imap processes will 'hang', consuming all available CPU time. It does not seem to 'finish' in any reasonable amount of time (in one instance I waited a few days). This process will not even exit gracefully, it needs to be killed with 'kill -9 <PID>'. It has just happened again. The output from gdb is: > # gdb attach 29401 > GNU gdb 6.3 > Copyright 2004 Free Software Foundation, Inc. > GDB is free software, covered by the GNU General Public License, and you are > welcome to change it and/or distribute copies of it under certain conditions. > Type "show copying" to see the conditions. > There is absolutely no warranty for GDB. Type "show warranty" for details. > This GDB was configured as "i586-suse-linux"...attach: No such file or directory. > > Attaching to process 29401 > Reading symbols from /usr/local/libexec/dovecot/imap...done. > Using host libthread_db library "/lib/tls/libthread_db.so.1". > Reading symbols from /lib/libdl.so.2...done. > Loaded symbols for /lib/libdl.so.2 > Reading symbols from /lib/tls/libc.so.6...done. > Loaded symbols for /lib/tls/libc.so.6 > Reading symbols from /lib/ld-linux.so.2...done. > Loaded symbols for /lib/ld-linux.so.2 > 0x0806049d in imap_sync_more (ctx=0x80d9770) at imap-sync.c:104 > 104 if (ctx->seq == 0) { > (gdb) bt full > #0 0x0806049d in imap_sync_more (ctx=0x80d9770) at imap-sync.c:104 > flags = 1075042320 > keywords = <value optimized out> > str = (string_t *) 0x80c31e0 > ret = 1 > #1 0x08060797 in cmd_sync_continue (cmd=0x80ccdbc) at imap-sync.c:207 > ctx = (struct cmd_sync_context *) 0x80cf000 > ret = <value optimized out> > #2 0x0805ad5a in _client_output (context=0x80ccd78) at client.c:465 > cmd = (struct client_command_context *) 0x80ccdbc > ret = 0 > #3 0x080af0bd in stream_send_io (context=0x80cceb0) at ostream-file.c:356 > ostream = (struct ostream *) 0x80ccee0 > ret = <value optimized out> > #4 0x080aa441 in io_loop_handler_run (ioloop=0x80cb9b0) at ioloop-epoll.c:203 > ctx = (struct ioloop_handler_context *) 0x80cb9d8 > list = (struct io_list *) 0x80d7780 > io = (struct io *) 0x80dc430 > tv = {tv_sec = 2, tv_usec = 540048} > events_count = 4 > t_id = 2 > msecs = <value optimized out> > ret = 1 > i = 0 > j = 1 > call = <value optimized out> > #5 0x080a9889 in io_loop_run (ioloop=0x80cb9b0) at ioloop.c:329 > No locals. > #6 0x08062087 in main (argc=1, argv=0xbffffaf4, envp=0xbffffafc) at main.c:290 > plugin_dir = <value optimized out> Mail log does not reveal anything immediately interesting. Thoughts? Server config ('dovecot -n -c /etc/dovecot/dovecot.conf'): > # 1.0.3: /etc/dovecot/dovecot.conf > base_dir: /var/run/dovecot/ > protocols: imap imaps pop3 pop3s > ssl_ca_file: /etc/ssl/current/cacert.pem > ssl_cert_file: /etc/ssl/current/server.pem > ssl_key_file: /etc/ssl/current/private.pem > disable_plaintext_auth: no > login_dir: /var/run/dovecot//login > login_executable(default): /usr/local/libexec/dovecot/imap-login > login_executable(imap): /usr/local/libexec/dovecot/imap-login > login_executable(pop3): /usr/local/libexec/dovecot/pop3-login > first_valid_uid: 50 > mail_debug: yes > mail_drop_priv_before_exec: yes > mail_executable(default): /usr/local/libexec/dovecot/imap > mail_executable(imap): /usr/local/libexec/dovecot/imap > mail_executable(pop3): /usr/local/libexec/dovecot/pop3 > mail_plugin_dir(default): /usr/local/lib/dovecot/imap > mail_plugin_dir(imap): /usr/local/lib/dovecot/imap > mail_plugin_dir(pop3): /usr/local/lib/dovecot/pop3 > mail_log_prefix: %Us(%u)(%p): > pop3_uidl_format(default): > pop3_uidl_format(imap): > pop3_uidl_format(pop3): %08Xu%08Xv > auth default: > debug_passwords: yes > passdb: > driver: passwd-file > args: /etc/dovecot/passwd > userdb: > driver: passwd-file > args: /etc/dovecot/passwd > socket: > type: listen > client: > path: /var/spool/postfix/private/auth > mode: 432 > user: postfix > group: postfix -- Best regards, Robert Tomanek mailto:rth23@poczta.onet.pl

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[Dovecot] mail_location backends
by Harrison Metzger 19 Nov '07

19 Nov '07

Hello, Where I work we have have an interesting setup, we have 2 machines with mail accounts on them and both have dovecot. We would really like to centralize all the mail accounts on one machine, but unfortunately the administration has not approved it. However, if we could create the "illusion" that they are on the same machine that would be acceptable. If we have a 3rd machine, lets say called mail.example.com, could we install dovecot on it (using LDAP authorization), such that when a user connects to this machine, it then connects to one of the 2 other machines to retrieve their mail (instead of reading from /var/spool/mail). So in essence, the mail backend is just another POP or IMAP server. In the ldap directory we could have a field that says the mail location is: "imap://machine1.example.com" for some users and "imap://machine2.example.com" (Of course it dosent have to look like that, but I hope you get my idea), then dovecot would make a connection to those servers and read the user's mail. Does such a backend even exist? Can dovecot's plugin support register a mail_location backend (such as mbox:/blah/blah, ...)? Harrison Metzger

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