First of all, I apologize for my accidental empty message earlier.
I just set up the SMTP submission proxy in Dovecot 2.3, but whenever I try to connect to it, it always returns "530 5.7.0 TLS required." for any sort of AUTH or MAIL command. This occurs even if TLS is being used. It also occurs regardless of whether I connect with a real client (Thunderbird) or manually with openssl s_client and regardless of whether a loopback connection or a remote connection is used. Here is the output of "dovecot -n". Please let me know if I can provide any other data. Thanks!
# 2.3.0.rc1 (12aba5948): /etc/dovecot/dovecot.conf # Pigeonhole version 0.5.0.alpha1 (f60f2785) # OS: Linux 4.14.7-041407-generic x86_64 Ubuntu Bionic Beaver (development branch) auth_mechanisms = plain login auth_username_format = %Ln mail_location = mdbox:~/mdbox managesieve_notify_capability = mailto managesieve_sieve_capability = fileinto reject envelope encoded-character vacation subaddress comparator-i;ascii-numeric relational regex imap4flags copy include variables body enotify environment mailbox date index ihave duplicate mime foreverypart extracttext namespace inbox { inbox = yes location = mailbox Drafts { special_use = \Drafts } mailbox Junk { special_use = \Junk } mailbox Sent { special_use = \Sent } mailbox "Sent Messages" { special_use = \Sent } mailbox Trash { special_use = \Trash } prefix = } passdb { driver = pam } plugin { sieve = file:~/sieve;active=~/.dovecot.sieve } postmaster_address = michael@michaelmarley.com protocols = imap sieve lmtp submission service auth { unix_listener /var/spool/postfix/private/dovecot-auth { group = postfix mode = 0660 user = postfix } } service imap-login { inet_listener imaps { port = 0 } } service lmtp { process_min_avail = 5 unix_listener /var/spool/postfix/private/dovecot-lmtp { group = postfix mode = 0600 user = postfix } } ssl = required ssl_cert =