Ok, got it.
change imap-login and pop-login to these like showed in dovocot wiki for
high-performance login mode.
service imap-login {
chroot = login
service_count = 0
client_limit = 600
process_limit = 100
process_min_avail = 16
}
service pop3-login {
Hello list,
i run here an large mailsetup with some million mailboxes and got strange
performance problems, cause i think i have overseen or forgotten an simple
setting.
Here are some details:
21 CentOS 7 Servers with dovecot 2.2.25 and ldap userdb/passdb via socket
behind an hardware loadbal