Greetings, I have had to reinstall my email server on another Linux (centos 7.6) VPS, with a newer version of dovecot, other software and a brand new letsencrypt certificate just for email withpostfix and dovecot (that certificate works fine with postfix). Output of dovecot --version and dovecot -n on the new server is below.
Now, messages ARE delivered in the right IMAP mailboxes, but when I try to connect with Mutt from my home computer, mutt says, before prompting for a password:
gnutls_handshake: A TLS fatal alert has been received.(Handshake failed)
the corresponding output of dovecot in /var/log/maillog is below. The gist of it **seems** to me to be the "no shared cipher" part, but I may be wrong. In any case, I have already tried to search online for that string, and other relevant parts of the log, without success. All I have found is suggestions to change the values of ssl_protocols and/or ssl_cipher_list to some non-default value, but I have tried all those tips without success. Current values of those variables are these:
grep -v ^# /etc/dovecot/conf.d/10-ssl.conf
ssl_cert = </etc/letsencrypt/live/MYSERVERNAME/fullchain.pem ssl_key = </etc/letsencrypt/live/MYSERVERNAME/privkey.pem ssl_protocols = !SSLv2 !SSLv3 ssl_cipher_list = ALL:!ADH:!LOW:!EXP:!aNULL:+HIGH:+MEDIU
any pointer to what to check or change next is VERY welcome.
Thanks in advance, Marco
################################################# Dec 8 10:53:43 MYSERVERNAME dovecot: imap-login: Debug: SSL: where=0x10, ret=1: before/accept initialization [47.53.159.60] Dec 8 10:53:43 MYSERVERNAME dovecot: imap-login: Debug: SSL: where=0x2001, ret=1: before/accept initialization [47.53.159.60] Dec 8 10:53:43 MYSERVERNAME dovecot: imap-login: Warning: SSL alert: where=0x4008, ret=552: fatal handshake failure [47.53.159.60] Dec 8 10:53:43 MYSERVERNAME dovecot: imap-login: Debug: SSL: where=0x2002, ret=-1: error [47.53.159.60] Dec 8 10:53:43 MYSERVERNAME dovecot: imap-login: Debug: SSL: where=0x2002, ret=-1: error [47.53.159.60] Dec 8 10:53:43 MYSERVERNAME dovecot: imap-login: Debug: SSL error: SSL_accept() failed: error:1408A0C1:SSL routines:ssl3_get_client_hello:no shared cipher Dec 8 10:53:43 MYSERVERNAME dovecot: imap-login: Disconnected (disconnected before auth was ready, waited 0 secs): user=<>, rip=47.53.159.60, lip=116.202.20.216, TLS handshaking: SSL_accept() failed: error:1408A0C1:SSL routines:ssl3_get_client_hello:no shared cipher, session=<knICtX98UK4vNZ88> Dec 8 10:53:43 MYSERVERNAME dovecot: auth: Debug: Loading modules from directory: /usr/lib64/dovecot/auth Dec 8 10:53:43 MYSERVERNAME dovecot: auth: Debug: Module loaded: /usr/lib64/dovecot/auth/lib20_auth_var_expand_crypt.so Dec 8 10:53:43 MYSERVERNAME dovecot: auth: Debug: Module loaded: /usr/lib64/dovecot/auth/libdriver_sqlite.so Dec 8 10:53:43 MYSERVERNAME dovecot: auth: Debug: Read auth token secret from /var/run/dovecot/auth-token-secret.dat Dec 8 10:53:43 MYSERVERNAME dovecot: auth: Debug: passwd-file /etc/imap.v_users: Read 1 users in 0 secs
################################################# dovecot --version 2.2.36 (1f10bfa63)
# 2.2.36 (1f10bfa63): /etc/dovecot/dovecot.conf # OS: Linux 3.10.0-957.1.3.el7.x86_64 x86_64 CentOS Linux release 7.6.1810 (Core) ext4 # Hostname: MYSERVERNAME auth_debug = yes auth_mechanisms = plain login auth_verbose = yes mail_location = maildir:/var/mail//base/ passdb { args = /etc/imap.v_users driver = passwd-file } service auth { unix_listener /var/spool/postfix/private/auth { group = postfix mode = 0660 user = postfix } } service imap-login { inet_listener imap { port = 0 } inet_listener imaps { port = 993 } } ssl = required userdb { args = /etc/imap.v_users driver = passwd-file } verbose_ssl = yes