SASL PLAIN authentication failed

/var/log/maillogに以下のエラーが出ている場合の対策

<エラー表示>

SASL PLAIN authentication failed

◻️以下の内容を追記すること

vi /etc/dovecot/conf.d/auth-system.conf.ext

================auth-system.conf.ext=======================

passdb {

  driver = pam

  # [session=yes] [setcred=yes] [failure_show_msg=yes] [max_requests=<n>]

  # [cache_key=<key>] [<service name>]

  #args = dovecot

  override_fields = allow_nets=127.0.0.0/8,::1/128,fe80::/64,192.168.1.0/24

  # 上記を加筆

}

========================================================

◻️以下の内容を確認する

/etc/postfix/10-auth.confの以下の内容通りになっているか確認する

===========10-auth-conf====================

# <doc/wiki/UserDatabase.txt>

#!include auth-deny.conf.ext

#!include auth-master.conf.ext

!include auth-system.conf.ext

#!include auth-sql.conf.ext

#!include auth-ldap.conf.ext

#!include auth-passwdfile.conf.ext

#!include auth-checkpassword.conf.ext

#!include auth-vpopmail.conf.ext

#!include auth-static.conf.ext

========================================

上記の設定の状態であれば、以下のような、認証表示になっていると思われる。

=============/var/log/maillog=============================

Dec 15 05:10:17 node-1 dovecot: auth: Debug: pam(user1,192.168.1.201): allow_nets: Matching for network 127.0.0.0/8

Dec 15 05:10:17 node-1 dovecot: auth: Debug: pam(user1,192.168.1.201): allow_nets: Matching for network ::1/128

Dec 15 05:10:17 node-1 dovecot: auth: Debug: pam(user1,192.168.1.201): allow_nets: Matching for network fe80::/64

Dec 15 05:10:17 node-1 dovecot: auth: Debug: pam(user1,192.168.1.201): allow_nets: Matching for network 192.168.1.0/24

======================================================================