Hi,
On 1 Mar 2018, at 17:39, ɹןʇnqן <lbutler+roundcube@covisp.net> wrote:
Mar 1 09:27:02 mail submit-tls/smtpd[86118]: connect from localhost[127.0.0.1] Mar 1 09:27:02 mail submit-tls/smtpd[86118]: SSL_accept error from localhost[127.0.0.1]: 0 Mar 1 09:27:02 mail submit-tls/smtpd[86118]: warning: TLS library problem: error:14094418:SSL routines:ssl3_read_bytes:tlsv1 alert unknown ca:/usr/src/crypto/openssl/ssl/s3_pkt.c:1493:SSL alert number 48: Mar 1 09:27:02 mail submit-tls/smtpd[86118]: lost connection after STARTTLS from localhost[127.0.0.1] Mar 1 09:27:02 mail submit-tls/smtpd[86118]: disconnect from localhost[127.0.0.1] ehlo=1 starttls=0/1 commands=1/2
The 'SSL alert number 48' indicates that the server certificate cannot be verified due to being issued by an unknown CA. This is probably caused by a missing, outdated or improperly configured CA bundle on the machine running Roundcube. You should be able to reproduce the problem with openssl s_client from that machine.
Kind regards,