In our low-traffic server we have always kept the default value for IMAP
mail_max_userip_connections (10).
The server has been working fine! (Thank you Timo for this!)
However, recently we have been having:
Maximum number of connections from user+IP exceeded
errors both for IMAP and webmail users.
Thus, we have now changed the value to 100.
The questions:
1.Might this lead to overloading the server?
2. Could another dovecot setting prevent the above setting from being
applied (e.g. due to connections exhaustion), i.e. should we also change
other setting(s)?
3. What should we take into account when deciding the value for
mail_max_userip_connections?
4. How can we set a different value to this directive for webmail
connections (coming from 127.0.0.1, ::1)?
The config follows for your reference (I've only changed the real domain
name).
Thanks in advance for your help.
Nick
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# doveconf -n
# 2.2.18: /etc/dovecot/dovecot.conf
# Pigeonhole version 0.4.8
# OS: Linux 2.6.18-407.el5 x86_64 CentOS release 5.11 (Final)
auth_mechanisms = plain login
auth_verbose = yes
disable_plaintext_auth = no
dsync_remote_cmd = ssh -l root vmail1.example.com doveadm dsync-server -u%u
mail_gid = 500
mail_location = maildir:~/Maildir/
mail_plugins = quota mail_log notify replication
mail_uid = 500
managesieve_notify_capability = mailto
managesieve_sieve_capability = fileinto reject envelope
encoded-character vacation subaddress comparator-i;ascii-numeric
relational regex imap4flags copy include variables body enotify
environment mailbox date index ihave duplicate
passdb {
args = /etc/dovecot/dovecot-passdb-ldap.conf
driver = ldap
}
plugin {
mail_log_events = delete undelete expunge copy mailbox_delete
mailbox_rename
mail_log_fields = uid box msgid size
mail_replica = remote:vm...@vmail1.example.com
quota = maildir:User quota
quota_rule = *:storage=5G
quota_rule2 = Trash:storage=+3%%
quota_warning = storage=75%% quota-warning 75 %u
quota_warning2 = storage=90%% quota-warning 90 %u
}
protocols = imap pop3
service aggregator {
fifo_listener replication-notify-fifo {
user = vmail
}
unix_listener replication-notify {
user = vmail
}
}
service auth {
unix_listener /var/spool/postfix/private/auth {
group = postfix
mode = 0660
user = postfix
}
unix_listener auth-master {
group = vmail
mode = 0660
user = vmail
}
user = root
}
service imap-login {
service_count = 1
vsz_limit = 64 M
}
service imap {
executable = imap postlogin
}
service pop3-login {
service_count = 1
vsz_limit = 64 M
}
service pop3 {
executable = pop3 postlogin
}
service postlogin {
executable = script-login -d rawlog
}
service quota-warning {
executable = script /opt/mail1.sh
unix_listener quota-warning {
user = vmail
}
user = vmail
}
service replicator {
process_min_avail = 1
unix_listener replicator-doveadm {
mode = 0600
}
}
ssl_ca = </etc/pki/tls/certs/chain-1552.pem
ssl_cert = </etc/pki/tls/certs/cert-1552.pem
ssl_key = </etc/pki/tls/private/key-1552.pem
ssl_protocols = !SSLv2 !SSLv3
syslog_facility = local1
userdb {
args = /etc/dovecot/dovecot-usrdb-ldap.conf
driver = ldap
}
protocol imap {
imap_client_workarounds = delay-newmail
mail_max_userip_connections = 100
mail_plugins = quota imap_quota notify replication
}
protocol pop3 {
mail_max_userip_connections = 3
mail_plugins = quota notify replication
pop3_client_workarounds = outlook-no-nuls oe-ns-eoh
pop3_uidl_format = %08Xu%08Xv
}
protocol lda {
auth_socket_path = /var/run/dovecot/auth-master
info_log_path =
log_path =
mail_plugins = quota notify replication
postmaster_address = sysad...@example.com
sendmail_path = /usr/lib/sendmail
}
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