On Thu, Jul 28, 2016 at 08:29:00PM +0200, Benny Pedersen wrote: > Jul 28 18:24:13 localhost postfix/smtpd[20024]: warning: TLS library > problem: error:14094412:SSL routines:ssl3_read_bytes:sslv3 alert bad > certificate:s3_pkt.c:1472:SSL alert number 42:
Thunderbird does not trust the server certificate, get a certificate it trusts. Perhaps the certificate uses SHA1 or MD5, or perhaps its issuer is not trusted? Or the hostname does not match, or the chain file is missing an intermediate certificate, ... You need to post the certificate chain and the Thunderbird SMTP settings for further help. -- Viktor.