Okay, I am really curious how this works then. Good catch on the 'www' test. I winged it without reading the manpage. I've never known a good starting point for learning DNS, so that is definitely a weak point. So, now that the DNS is out of the way. I'm going to dig deeper here.
When I try to send a message to myself using Thunderbird, [email protected], I get this Sending of the message failed. The message could not be sent using Outgoing server (SMTP) example.com for an unknown reason. Please verify that your Outgoing server (SMTP) settings are correct and try again. Then about half a second later, a popup window appears titled 'Add security exception' that begins "You are about to override how Thunderbird identifies this site". I click on 'Get Certificate', but it doesn't really do anything. So I look in the logs: mail.log Nov 28 18:34:56 example dovecot: imap-login: Login: user=<[email protected]>, method=PLAIN, rip=69.179.xxx.yyy, lip=192.168.178.31, mpid=1291, TLS, session=<gfbp419CFsRFs3SF> Nov 28 18:35:14 example postfix/smtpd[1293]: connect from 69-179-xxx-yyy.dyn.centurytel.net[69.179.xxx.yyy] Nov 28 18:35:16 example postfix/smtpd[1293]: warning: TLS library problem: error:14094418:SSL routines:ssl3_read_bytes:tlsv1 alert unknown ca:s3_pkt.c:1472:SSL alert number 48: Nov 28 18:35:16 example postfix/smtpd[1293]: lost connection after STARTTLS from 69-179-xxx-yyy.dyn.centurytel.net[69.179.xxx.yyy] Nov 28 18:35:16 example postfix/smtpd[1293]: disconnect from 69-179-xxx-yyy.dyn.centurytel.net[69.179.xxx.yyy] ehlo=1 starttls=1 commands=2 I have no idea what this means. The only other log file with a recent entry would be the auth.log which seems to only detail the 20 or so attempts of SSH login each minute from across the world, which is normal for anybody with a website. Rick On 11/28/2016 at 11:12 AM, "Noel Jones" <[email protected]> wrote: > >On 11/28/2016 9:07 AM, [email protected] wrote: >> Hello, >> >> First, email has been working fine on this server for past >several months while using the Squirrelmail web client located on >the same server. I am needing an alternative method to access >mail services and decided, on a whim, to try Thunderbird. >Thunderbird interacted with the Dovecot IMAP server just fine, but >when I tried to test sending mail over SMTP, it failed. I wish the >error they gave me was more verbose, but it wasn't. So I decided >to test things in more detail. >> >> I decided that, since SMTP is a plain-text protocol, I should be >able to interact via telnet. Searching on this idea, I found a >really interesting webpage >> >> https://www.port25.com/how-to-check-an-smtp-connection-with-a- >manual-telnet-session-2/ >> >> There was something strange with the MX record. I modified the >URL, of course. >> >> nslookup -type=mx example.com >> Server: 8.8.8.8 >> Address: 8.8.8.8#53 >> >> Non-authoritative answer: >> example.com mail exchanger = 10 mail.example.com. >> >> Authoritative answers can be found from: >> >> >> and that was it. > >Nothing wrong here, MX records don't contain an IP. You can >compare >with -type=mx gmail.com. > > >> >> I decided to perform the same test, but pull the www record and >with that I actually got an IP address. >> >> nslookup -type=www example.com >> unknown query type: www >> Server: 8.8.8.8 >> Address: 8.8.8.8#53 >> >> Non-authoritative answer: >> Name: example.com >> Address: 87.xxx.yyy.zzz >> > >There is no type=www. This test is broken. > > >http://www.postfix.org/DEBUG_README.html > >If you show postfix logs and describe the actual error you're >getting, maybe someone can help. >http://www.postfix.org/DEBUG_README.html#mail > > > -- Noel Jones
