Issue with one user only, exceeding connections
Jeremy Schaeffer
kb9mfd at phonesplus.biz
Wed Jun 8 19:14:23 UTC 2022
I keep having this issue with one user, and I have to restart dovecot
several times a day to clear it. What I have is a postfix / dovecot mail
server (Centos 7) and about a dozen users. All mailboxes are imap ssl. I
monitor about 4 mailboxes on my computer and tablet. I use Thunderbird
on the computer (cache connections at 2) and K9 on the tablet, but one
user of the four I keep getting "Maximum number of connections from
user+IP exceeded" and I have the maximum at 50
"(mail_max_userip_connections=50)" so its hard for me to believe I am
actually exceeding it unless dovecot/client is not dropping connections
and keeps starting new ones until it reaches the maximum, but again,
only for one user, even though I am monitoring 4 on the same devices.
Any idea how to troubleshoot this? I don't know if I should be looking
at dovecot or the clients, or what I need to look for. It's been going
on since I put this server in use over a year ago. I also have issues
with Outlook clients disconnecting, just outlook, is there any
recommended settings to make Outlook work smoother?
Thanks! - Jeremy
Config -
# 2.2.36 (1f10bfa63): /etc/dovecot/dovecot.conf
# OS: Linux 3.10.0-1160.11.1.el7.x86_64 x86_64 CentOS Linux release
7.9.2009 (Core)
# Hostname: ***
auth_mechanisms = plain login
debug_log_path = /var/log/dovecot_debug.log
first_valid_gid = 500
last_valid_gid = 600
last_valid_uid = 600
listen = *
mail_location = maildir:~/Maildir
mbox_write_locks = fcntl
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 = INBOX.
separator = .
}
passdb {
driver = pam
}
pop3_uidl_format = %f
protocols = imap lmtp
service auth {
unix_listener /var/spool/postfix/private/auth {
group = postfix
mode = 0660
user = postfix
}
}
service imap-login {
inet_listener imap {
port = 143
}
inet_listener imaps {
port = 993
ssl = yes
}
process_min_avail = 1
service_count = 0
}
service imap {
process_limit = 1024
}
service lmtp {
unix_listener lmtp {
mode = 0666
}
}
ssl = required
ssl_cert = <***
ssl_cipher_list = ECDHE-RSA-CHACHA20-POLY1305:ALL:!LOW:!SSLv2:!EXP:!aNULL
ssl_key = # hidden, use -P to show it
ssl_prefer_server_ciphers = yes
userdb {
driver = passwd
}
protocol imap {
mail_max_userip_connections = 50
}
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