Hi,

last friday I upgraded from dovecot-2.3.10.1_2 to dovecot-2.3.11.3 (FreeBSD).

Since then, I started having some issues with some customers.

The log I see is like:

pop3-login: Disconnected (tried to use unsupported auth mechanism): user=<username@domain.it>, method=USER, rip=x,y,x,z, lip=x,y,w,z, session=<e5KkR5qto8hPAL9q>

While, before upgrade, same user logged succesfully:

pop3-login: Login: user=<username@domain.it>, method=PLAIN, rip=x,y,x,z, lip=x,y,w,z, mpid=62876, session=<dMRmGWCtFtJtdcy6>

This is my conf (unchanged since months):

# dovecot -n
# 2.3.11.3 (502c39af9): /usr/local/etc/dovecot/dovecot.conf
# OS: FreeBSD 12.1-RELEASE-p8 amd64 zfs
# Hostname: server
doveconf: Warning: please set ssl_dh=</usr/local/etc/dovecot/dh.pem
doveconf: Warning: You can generate it with: dd if=/var/db/dovecot/ssl-parameters.dat bs=1 skip=88 | openssl dhparam -inform der > /usr/local/etc/dovecot/dh.pem
auth_mechanisms = plain login digest-md5 cram-md5
auth_verbose = yes
auth_verbose_passwords = yes
default_client_limit = 2000
default_process_limit = 500
default_vsz_limit = 512 M
disable_plaintext_auth = no
first_valid_gid = 125
first_valid_uid = 125
imap_id_log = *
mail_gid = 1003
mail_location = maildir:/mail/domains
mail_privileged_group = postfix
mail_uid = 1003
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 {
args = /usr/local/etc/dovecot/dovecot-sql.conf.ext
driver = sql
}
passdb {
args = /etc/dovecot/dovecot-sql-crypt.conf.ext
driver = sql
}
service auth {
unix_listener /var/spool/postfix/private/auth {
group = postfix
mode = 0666
user = postfix
}
unix_listener auth-userdb {
group = postfix
mode = 0600
user = postfix
}
}
service imap {
process_limit = 1024
}
service lmtp {
unix_listener /var/spool/postfix/private/dovecot-lmtp {
group = postfix
mode = 0600
user = postfix
}
}
ssl_cert = </etc/ssl/wildcard.domain.net_bundle.crt
ssl_dh = # hidden, use -P to show it
ssl_key = # hidden, use -P to show it
userdb {
args = /usr/local/etc/dovecot/dovecot-sql.conf.ext
driver = sql
}
protocol imap {
mail_max_userip_connections = 100
}

any help?

Thank you!