Verification that certificate works
https://forum.linode.com/viewtopic.php?t=8501
[root@drasnar mail]# openssl s_client -connect smtp.gmail.com:25 -starttls smtp -CApath /etc/ssl/certs
CONNECTED(00000003)
depth=2 C = US, O = GeoTrust Inc., CN = GeoTrust Global CA
verify error:num=20:unable to get local issuer certificate
verify return:0
result in /var/log/maillog
Oct 12 20:21:38 localhost sendmail[7943]: r9CILcO4007943: from=jandra, size=277,, nrcpts=1, msgid=<201310121821.r9CILcO4007943@drasnar.cz>, relay=root@localhost
Oct 12 20:21:38 localhost sendmail[7944]: r9CILc65007944: from=<jandra@drasnar.cz>, size=516,, nrcpts=1, msgid=<201310121821.r9CILcO4007943@drasnar.cz>, proto=ESMTP, daemon=MTA, relay=drasnar.cz [127.0.0.1]
Oct 12 20:21:38 localhost sendmail[7943]: r9CILcO4007943: to=jan.drasnar@gmail.com, ctladdr=jandra (1000/1000), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=30277, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (r9CILc65007944 Message accepted for delivery)
Oct 12 20:21:39 localhost sendmail[7946]: STARTTLS=client: file /etc/mail/certs/mykey.pem unsafe: Group readable file
Oct 12 20:21:39 localhost sendmail[7946]: STARTTLS=client, relay=smtp.gmail.com, version=TLSv1/SSLv3, verify=FAIL, cipher=RC4-SHA, bits=128/128
Oct 12 20:21:40 localhost sendmail[7946]: r9CILc65007944: to=<jan.drasnar@gmail.com>, ctladdr=<jandra@drasnar.cz> (1000/1000), delay=00:00:02, xdelay=00:00:02, mailer=relay, pri=120516, relay=smtp.gmail.com [173.194.70.108], dsn=2.0.0, stat=Sent (OK 1381602100 h45sm130451195eeg.5 – gsmtp)
