Okay, I'm made some exciting progress and I am grateful for the help. I will
show to people how I got this working
At first thought, I figured that it would simply be the IMAP password used by
Dovecot to access my mailbox. Not exactly true... I did some digging in some
blogs and the documentation for Dovecot and Postfix. I configured Dovecot to
authenticate using a SHA512 encrypted password in a SQL database, just as was
posted in a blog some time back (Reference 1). I found out that I can have
SASL authentication for Postfix via Dovecot. I made a few changes according to
a blog post (Reference 2)
I can send and receive mail from Thunderbird now, which resolves this long and
tortured thread.
For the good of the internet community, I am sharing my configuration in it's
working state.
After all this, my main.cf has evolved to become:
mydomain = example.com
smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
biff = no
append_dot_mydomain = no
readme_directory = no
# TLS parameters
smtpd_tls_security_level = may
smtpd_tls_loglevel = 1
smtpd_tls_cert_file=/etc/letsencrypt/live/example.com/fullchain.pem
smtpd_tls_key_file=/etc/letsencrypt/live/example.com/privkey.pem
#smtpd_use_tls=yes
#smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
#Added December 1, 2016 TLS parameters
smtpd_tls_received_header = yes
smtpd_tls_auth_only = no
smtpd_use_tls=yes
smtp_tls_note_starttls_offer = yes
smtpd_tls_session_cache_timeout = 3600s
#end December 1, 2016 TLS parameters
smtpd_relay_restrictions = permit_mynetworks permit_sasl_authenticated
defer_unauth_destination
myhostname = example.com
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
myorigin = /etc/mailname
#mydestination = $myhostname, example.com, localhost.com, , localhost
mydestination = localhost
relayhost =
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = all
inet_protocols = all
virtual_transport = lmtp:unix:private/dovecot-lmtp
virtual_mailbox_domains = mysql:/etc/postfix/mysql-virtual-mailbox-domains.cf
virtual_mailbox_maps = mysql:/etc/postfix/mysql-virtual-mailbox-maps.cf
virtual_alias_maps = mysql:/etc/postfix/mysql-virtual-alias-maps.cf
#Added December 1 to enable SASL with Dovecot
smtpd_sasl_type = dovecot
smtpd_sasl_path = private/auth
smtpd_sasl_local_domain = example.com
smtpd_sasl_security_options = noanonymous
broken_sasl_auth_clients = yes
smtpd_sasl_auth_enable = yes
smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated,
reject_unauth_destination
#End December 1 SASL/Dovecot parameters
and the master.cf has become:
==========================================================================
# service type private unpriv chroot wakeup maxproc command + args
# (yes) (yes) (no) (never) (100)
# ==========================================================================
smtp inet n - y - - smtpd
submission inet n - n - - smtpd
-o syslog_name=postfix/submission
-o smtpd_tls_security_level=encrypt
-o smtpd_sasl_auth_enable=yes
-o smtpd_recipient_restrictions=permit_sasl_authenticated,reject
-o milter_macro_daemon_name=ORIGINATING
pickup unix n - y 60 1 pickup
cleanup unix n - y - 0 cleanup
qmgr unix n - n 300 1 qmgr
tlsmgr unix - - y 1000? 1 tlsmgr
rewrite unix - - y - - trivial-rewrite
bounce unix - - y - 0 bounce
defer unix - - y - 0 bounce
trace unix - - y - 0 bounce
verify unix - - y - 1 verify
flush unix n - y 1000? 0 flush
proxymap unix - - n - - proxymap
proxywrite unix - - n - 1 proxymap
smtp unix - - y - - smtp
relay unix - - y - - smtp
showq unix n - y - - showq
error unix - - y - - error
retry unix - - y - - error
discard unix - - y - - discard
local unix - n n - - local
virtual unix - n n - - virtual
lmtp unix - - y - - lmtp
anvil unix - - y - 1 anvil
scache unix - - y - 1 scache
maildrop unix - n n - - pipe
flags=DRhu user=vmail argv=/usr/bin/maildrop -d ${recipient}
uucp unix - n n - - pipe
flags=Fqhu user=uucp argv=uux -r -n -z -a$sender - $nexthop!rmail ($recipient)
ifmail unix - n n - - pipe
flags=F user=ftn argv=/usr/lib/ifmail/ifmail -r $nexthop ($recipient)
bsmtp unix - n n - - pipe
flags=Fq. user=bsmtp argv=/usr/lib/bsmtp/bsmtp -t$nexthop -f$sender $recipient
scalemail-backend unix - n n - 2 pipe
flags=R user=scalemail argv=/usr/lib/scalemail/bin/scalemail-store ${nexthop}
${user} ${extension}
mailman unix - n n - - pipe
flags=FR user=list argv=/usr/lib/mailman/bin/postfix-to-mailman.py
${nexthop} ${user}
References:
(1)
https://www.digitalocean.com/community/tutorials/how-to-configure-a-mail-server-using-postfix-dovecot-mysql-and-spamassassin
(2) http://xmodulo.com/enable-user-authentication-postfix-smtp-server-sasl.html
