Problem to login to email accounts and the system shows this error message:

Plaintext authentication disallowed on non-secure (SSL/TLS) connections
If you do not want to use SSL/TLS connection to get your email, and to disable SSL/TLS secure connection, do the following:

>> Edit dovecot configuration file: /etc/dovecot.conf using your favorite Linux editor such as vi or pico.

>> Change the value for this directive from:

disable_plaintext_auth = yes
TO:
disable_plaintext_auth = no

Restart service dovecot and exim
# /etc/init.d/dovecot restart
# /etc/init.d/exim restart