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Allow secure or insecure POP3/IMAP/SMTP connections without or with STARTTLS
It's strongly recommended to use only POP3S/IMAPS for better security.
Allow insecure POP3/IMAP connections
If you want to enable POP3/IMAP services without STARTTLS for some reason, update below two parameters in Dovecot config file /etc/dovecot/dovecot.conf and restart Dovecot service:
- on Linux and OpenBSD, it's
/etc/dovecot/dovecot.conf - on FreeBSD, it's
/usr/local/etc/dovecot/dovecot.conf
disable_plaintext_auth=no
ssl=yes
Again, it's strongly recommended to use only POP3S/IMAPS for better security.
Default and recommended:
disable_plaintext_auth=yes
ssl=required
Allow insecure SMTP connection
Please comment out lines below in Postfix config file /etc/postfix/main.cf and reload or restart Postfix service:
smtpd_tls_auth_only=yes