The link you provided only talks about enabling SASL and ensuring the firewall allows POP and IMAP - it does not actually configure them.
You will probably need to edit dovecot.conf and add / uncomment the appropriate lines with the various services. For example, my config, which does work with POP and IMAP looks like:
auth_default_realm = host.name
auth_mechanisms = plain login
auth_verbose = yes
disable_plaintext_auth = no
listen = *
log_timestamp = "%Y-%m-%d %H:%M:%S "
login_greeting = Server ready.
mail_max_userip_connections = 30
# mail_location = maildir:~/Maildir
# mail_location = maildir:/path/to/%u
mail_location = maildir:/path/to/%u/Maildir
mail_privileged_group = mail
passdb {
args = /etc/dovecot/dovecot-sql.conf
driver = sql
}
plugin {
sieve = ~/.dovecot.sieve
sieve_dir = ~/sieve
}
service lmtp {
user=mailuser
process_min_avail = 5
inet_listener lmtp {
address=127.0.0.1
port = 24
}
unix_listener lmtp {
# mode=666
}
}
protocols = imap pop3 sieve lmtp
service auth {
unix_listener /var/spool/postfix/private/auth {
group = postfix
mode = 0660
user = postfix
}
unix_listener auth-master {
mode = 0600
user = mailuser
}
}
service imap-login {
chroot = login
user = dovecot
}
service pop3-login {
chroot = login
user = dovecot
}
ssl_ca = </etc/ssl-keys/my-required-PositiveChain.crt
ssl_cert = </etc/ssl-keys/mail.networksavvy.org.crt
ssl_cipher_list = ALL:!LOW:!SSLv2:ALL:!aNULL:!ADH:!eNULL:!EXP:RC4+RSA:+HIGH:+MEDIUM
ssl_key = </etc/ssl-keys/my.host.key
userdb {
args = /etc/dovecot/dovecot-sql.conf
driver = sql
}
verbose_ssl = no
protocol imap {
disable_plaintext_auth = no
imap_client_workarounds = delay-newmail
mail_max_userip_connections = 50
}
protocol pop3 {
disable_plaintext_auth = no
mail_max_userip_connections = 50
pop3_client_workarounds = outlook-no-nuls oe-ns-eoh
pop3_uidl_format = %08Xu%08Xv
ssl_ca = </etc/ssl-keys/my-PositiveChain.crt
ssl_cert = </etc/ssl-keys/my.host.crt
ssl_key = </etc/ssl-keys/my.host.key
}
protocol lda {
auth_socket_path = /var/run/dovecot/auth-master
deliver_log_format = msgid=%m: %$
hostname = my.host.name
postmaster_address = postmaster
quota_full_tempfail = yes
rejection_reason = Your message to <%t> was automatically rejected:%n%r
}
Note the "protocol" and "service" lines.