Thanks all for the quick and knowledgeable replies!
More details on my system: the imap folders, but the former is found on local disk on /var/mail.
- Debian 7.1 server hosting many daemons which do not show any slow behavior at all (apache, postfix, nfs, autofs, ssh, ...), nor is it slow to run any application for test (no resource intensive application is run routinely on this machine due to its low 4Gb RAM, in any case)
- /home partition nfs mounted from a remote firewalled QNAP NAS server (TS-869U-RP), which also serves other machines (RAID-5 setup with currently no bad disks). When logging in as user in any of those machines including the dovecot server, I notice no delay (remember that dovecot hangs for 60 or more seconds). Also, the inbox hangs as often as
- user authentification using ldap with a daemon hosted on a different server than dovecot's (and firewalled from the outside)
- the logs files give no warnings or errors other than the typical failed connection attempts from chinese or so hackers. I do however, find the following lines in mail.log every once in a while:
Sep 26 11:02:20 wasabi dovecot: imap(pato): Disconnected: Disconnected in IDLE in=8017978 out=490892
Sep 26 11:02:21 wasabi dovecot: imap-login: Login: user=<pato>, method=PLAIN, rip=24.58.62.118, lip=146.83.9.56, mpid=3964, TLS, session\
=<lcGR0UnnugAYOj52>
Sep 26 11:03:23 wasabi dovecot: imap-login: Disconnected (no auth attempts in 1 secs): user=<>, rip=24.58.62.118, lip=146.83.9.56, TLS, \
session=<uOJE1UnnxQAYOj52>
Sep 26 11:03:26 wasabi dovecot: imap-login: Login: user=<pato>, method=PLAIN, rip=24.58.62.118, lip=146.83.9.56, mpid=3973, TLS, session\
=<PCFr1UnnxgAYOj52>
Sep 26 11:05:00 wasabi dovecot: imap(pato): Disconnected: Disconnected in IDLE in=1205 out=28366
note how it receives a 'user=<>' from the same ip it received a valid user a minute ago (and this is the timescale of my problem). though.
- When the problem started I did a lot of rather simultaneous changes to my system (change the hardware of my dovecot's host, moved the ldap daemon from the dovecot machine to a firewalled machine, installed the QNAP NAS, updated CA certificate ...), so it is hard to pinpoint the cause of this. Every other daemon is working as good as it was before,
- 'doveconf -n' output is below.
Thank you very much!!
PatricioPS: Please warn me if any of the information I have given can be used to exploit my system. I have tried to be very careful with this
# 2.1.7: /etc/dovecot/dovecot.conf # OS: Linux 3.2.0-4-amd64 x86_64 Debian 7.1 mail_location = mbox:~/mail:INBOX=/var/mail/%u mail_privileged_group = mail 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 } protocols = " imap" service auth { inet_listener { port = 12345 } unix_listener /var/spool/postfix/private/auth { group = postfix mode = 0666 user = postfix } } ssl_cert = </etc/dovecot/wasabi.imap.crt ssl_key = </etc/dovecot/private/wasabi.imap.nopwd.key userdb { driver = passwd }