I recently did a task for my development team's website (ironfi.st), in which I set us up an SMTP mail server on an apache2 web server. I used sendmail to complete the task along with a WordPress SMTP plugin called WP-MAIL-SMTP to allow for functionality of a contact page on our website. However, the current issue I am facing is that no mail will send out from the server. One of the reasons I chose sendmail is due to it's simple setup steps. So I'm having trouble pinpointing what I might have done incorrectly. I connected to the server via Ubuntu and installed sendmail onto it. After which I ran the configuration setup and then went to edit the hosts file in /etc/hosts.Below is a copy of what I put into the hosts file:127.0.1.1 ironfi.st ironfi.st127.0.0.1 localhost localhost.localdomain ironfi.stUpon doing this I went and tested the SMTP server using the send test email feature that comes with the WP plugin I'm using. As stated previously, the email did not send. I began reading through the logs that the plugin spat out. However, this area is not necessarily my skilled area, so I may have missed something in the logs, which is why I'm attaching both the logs I took directly from the latest SMTP server log file mail.log from /var/log and the log files from the plugin below:Logs from the plugin:Test Message SentThe result was:bool(false)The full debugging output is shown below:object(PHPMailer)#445 (75) {  [Version]=>  string(6) 5.2.14  [Priority]=>  NULL  [CharSet]=>  string(10) iso-8859-1  [ContentType]=>  string(10) text/plain  [Encoding]=>  string(4) 8bit  [ErrorInfo]=>  string(0)   [From]=>  string(14) root@localhost  [FromName]=>  string(9) Root User  [Sender]=>  string(0)   [ReturnPath]=>  string(0)   [Subject]=>  string(0)   [Body]=>  string(0)   [AltBody]=>  string(0)   [Ical]=>  string(0)   [MIMEBody:protected]=>  string(0)   [MIMEHeader:protected]=>  string(0)   [mailHeader:protected]=>  string(0)   [WordWrap]=>  int(0)  [Mailer]=>  string(4) mail  [Sendmail]=>  string(18) /usr/sbin/sendmail  [UseSendmailOptions]=>  bool(true)  [PluginDir]=>  string(0)   [ConfirmReadingTo]=>  string(0)   [Hostname]=>  string(0)   [MessageID]=>  string(0)   [MessageDate]=>  string(0)   [Host]=>  string(9) localhost  [Port]=>  int(25)  [Helo]=>  string(0)   [SMTPSecure]=>  string(0)   [SMTPAutoTLS]=>  bool(true)  [SMTPAuth]=>  bool(false)  [SMTPOptions]=>  array(0) {  }  [Username]=>  string(0)   [Password]=>  string(0)   [AuthType]=>  string(0)   [Realm]=>  string(0)   [Workstation]=>  string(0)   [Timeout]=>  int(300)  [SMTPDebug]=>  bool(true)  [Debugoutput]=>  string(4) echo  [SMTPKeepAlive]=>  bool(false)  [SingleTo]=>  bool(false)  [SingleToArray]=>  array(0) {  }  [do_verp]=>  bool(false)  [AllowEmpty]=>  bool(false)  [LE]=>  string(1)   [DKIM_selector]=>  string(0)   [DKIM_identity]=>  string(0)   [DKIM_passphrase]=>  string(0)   [DKIM_domain]=>  string(0)   [DKIM_private]=>  string(0)   [action_function]=>  string(0)   [XMailer]=>  string(0)   [smtp:protected]=>  NULL  [to:protected]=>  array(0) {  }  [cc:protected]=>  array(0) {  }  [bcc:protected]=>  array(0) {  }  [ReplyTo:protected]=>  array(0) {  }  [all_recipients:protected]=>  array(0) {  }  [RecipientsQueue:protected]=>  array(0) {  }  [ReplyToQueue:protected]=>  array(0) {  }  [attachment:protected]=>  array(0) {  }  [CustomHeader:protected]=>  array(0) {  }  [lastMessageID:protected]=>  string(0)   [message_type:protected]=>  string(0)   [boundary:protected]=>  array(0) {  }  [language:protected]=>  array(0) {  }  [error_count:protected]=>  int(0)  [sign_cert_file:protected]=>  string(0)   [sign_key_file:protected]=>  string(0)   [sign_extracerts_file:protected]=>  string(0)   [sign_key_pass:protected]=>  string(0)   [exceptions:protected]=>  bool(true)  [uniqueid:protected]=>  string(0) }mail.log:Feb  5 10:56:28 ironfist-droplet sendmail[27655]: v15FuS0k027655: from=root, size=196, class=0, nrcpts=1, msgid=<201702051556.v15FuS0k027655@ironfist-droplet>, relay=root@localhostFeb  5 10:56:28 ironfist-droplet sm-mta[27657]: v15FuSaG027657: ruleset=check_rcpt, arg1=<root@ironfist-droplet>, relay=localhost [127.0.0.1], reject=553 5.1.8 <root@ironfist-droplet>... Domain of sender address root@ironfist-droplet does not existFeb  5 10:56:28 ironfist-droplet sendmail[27655]: v15FuS0k027655: to=root, ctladdr=root (0/0), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=30196, relay=[127.0.0.1] [127.0.0.1], dsn=5.1.8, stat=User unknownFeb  5 10:56:28 ironfist-droplet sm-mta[27657]: v15FuSaG027657: from=<root@ironfist-droplet>, size=196, class=0, nrcpts=0, proto=ESMTP, daemon=MTA-v4, relay=localhost [127.0.0.1]Feb  5 10:56:28 ironfist-droplet sendmail[27655]: v15FuS0k027655: v15FuS0l027655: DSN: User unknownFeb  5 10:56:28 ironfist-droplet sm-mta[27657]: v15FuSaI027657: from=<>, size=2194, class=0, nrcpts=1, msgid=<201702051556.v15FuS0l027655@ironfist-droplet>, proto=ESMTP, daemon=MTA-v4, relay=localhost [127.0.0.1]Feb  5 10:56:28 ironfist-droplet sendmail[27655]: v15FuS0l027655: to=root, delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=31220, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (v15FuSaI027657 Message accepted for delivery)Feb  5 10:56:28 ironfist-droplet sm-mta[27658]: v15FuSaI027657: to=<root@ironfist-droplet>, delay=00:00:00, xdelay=00:00:00, mailer=local, pri=32407, dsn=2.0.0, stat=SentFeb  5 11:03:40 ironfist-droplet sendmail[27694]: v15G3ehZ027694: from=root, size=196, class=0, nrcpts=1, msgid=<201702051603.v15G3ehZ027694@ironfist-droplet>, relay=root@localhostFeb  5 11:03:40 ironfist-droplet sm-mta[27696]: v15G3e0P027696: ruleset=check_rcpt, arg1=<root@ironfist-droplet>, relay=localhost [127.0.0.1], reject=553 5.1.8 <root@ironfist-droplet>... Domain of sender address root@ironfist-droplet does not existFeb  5 11:03:40 ironfist-droplet sendmail[27694]: v15G3ehZ027694: to=root, ctladdr=root (0/0), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=30196, relay=[127.0.0.1] [127.0.0.1], dsn=5.1.8, stat=User unknownFeb  5 11:03:40 ironfist-droplet sm-mta[27696]: v15G3e0P027696: from=<root@ironfist-droplet>, size=196, class=0, nrcpts=0, proto=ESMTP, daemon=MTA-v4, relay=localhost [127.0.0.1]Feb  5 11:03:40 ironfist-droplet sendmail[27694]: v15G3ehZ027694: v15G3eha027694: DSN: User unknownFeb  5 11:03:40 ironfist-droplet sm-mta[27696]: v15G3e0R027696: from=<>, size=2194, class=0, nrcpts=1, msgid=<201702051603.v15G3eha027694@ironfist-droplet>, proto=ESMTP, daemon=MTA-v4, relay=localhost [127.0.0.1]Feb  5 11:03:40 ironfist-droplet sendmail[27694]: v15G3eha027694: to=root, delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=31220, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (v15G3e0R027696 Message accepted for delivery)Feb  5 11:03:40 ironfist-droplet sm-mta[27697]: v15G3e0R027696: to=<root@ironfist-droplet>, delay=00:00:00, xdelay=00:00:00, mailer=local, pri=32407, dsn=2.0.0, stat=SentFeb  5 11:04:30 ironfist-droplet sendmail[27702]: v15G4Uxv027702: from=root, size=196, class=0, nrcpts=1, msgid=<201702051604.v15G4Uxv027702@ironfist-droplet>, relay=root@localhostFeb  5 11:04:30 ironfist-droplet sm-mta[27704]: v15G4UL7027704: ruleset=check_rcpt, arg1=<root@ironfist-droplet>, relay=localhost [127.0.0.1], reject=553 5.1.8 <root@ironfist-droplet>... Domain of sender address root@ironfist-droplet does not existFeb  5 11:04:30 ironfist-droplet sendmail[27702]: v15G4Uxv027702: to=root, ctladdr=root (0/0), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=30196, relay=[127.0.0.1] [127.0.0.1], dsn=5.1.8, stat=User unknownFeb  5 11:04:30 ironfist-droplet sm-mta[27704]: v15G4UL7027704: from=<root@ironfist-droplet>, size=196, class=0, nrcpts=0, proto=ESMTP, daemon=MTA-v4, relay=localhost [127.0.0.1]Feb  5 11:04:30 ironfist-droplet sendmail[27702]: v15G4Uxv027702: v15G4Uxw027702: DSN: User unknownFeb  5 11:04:30 ironfist-droplet sm-mta[27704]: v15G4UL9027704: from=<>, size=2194, class=0, nrcpts=1, msgid=<201702051604.v15G4Uxw027702@ironfist-droplet>, proto=ESMTP, daemon=MTA-v4, relay=localhost [127.0.0.1]Feb  5 11:04:30 ironfist-droplet sendmail[27702]: v15G4Uxw027702: to=root, delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=31220, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (v15G4UL9027704 Message accepted for delivery)Feb  5 11:04:30 ironfist-droplet sm-mta[27705]: v15G4UL9027704: to=<root@ironfist-droplet>, delay=00:00:00, xdelay=00:00:00, mailer=local, pri=32407, dsn=2.0.0, stat=SentFeb  5 11:04:43 ironfist-droplet sendmail[27710]: v15G4hPh027710: from=root, size=196, class=0, nrcpts=1, msgid=<201702051604.v15G4hPh027710@ironfist-droplet>, relay=root@localhostFeb  5 11:04:43 ironfist-droplet sm-mta[27712]: v15G4hZC027712: ruleset=check_rcpt, arg1=<root@ironfist-droplet>, relay=localhost [127.0.0.1], reject=553 5.1.8 <root@ironfist-droplet>... Domain of sender address root@ironfist-droplet does not existFeb  5 11:04:43 ironfist-droplet sendmail[27710]: v15G4hPh027710: to=root, ctladdr=root (0/0), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=30196, relay=[127.0.0.1] [127.0.0.1], dsn=5.1.8, stat=User unknownFeb  5 11:04:43 ironfist-droplet sm-mta[27712]: v15G4hZC027712: from=<root@ironfist-droplet>, size=196, class=0, nrcpts=0, proto=ESMTP, daemon=MTA-v4, relay=localhost [127.0.0.1]Feb  5 11:04:43 ironfist-droplet sendmail[27710]: v15G4hPh027710: v15G4hPi027710: DSN: User unknownFeb  5 11:04:43 ironfist-droplet sm-mta[27712]: v15G4hZE027712: from=<>, size=2194, class=0, nrcpts=1, msgid=<201702051604.v15G4hPi027710@ironfist-droplet>, proto=ESMTP, daemon=MTA-v4, relay=localhost [127.0.0.1]Feb  5 11:04:43 ironfist-droplet sendmail[27710]: v15G4hPi027710: to=root, delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=31220, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (v15G4hZE027712 Message accepted for delivery)Feb  5 11:04:43 ironfist-droplet sm-mta[27713]: v15G4hZE027712: to=<root@ironfist-droplet>, delay=00:00:00, xdelay=00:00:00, mailer=local, pri=32407, dsn=2.0.0, stat=SentFeb  5 11:06:52 ironfist-droplet sendmail[27722]: v15G6qmc027722: from=root, size=196, class=0, nrcpts=1, msgid=<201702051606.v15G6qmc027722@ironfist-droplet>, relay=root@localhostFeb  5 11:06:52 ironfist-droplet sm-mta[27724]: v15G6qtl027724: ruleset=check_rcpt, arg1=<root@ironfist-droplet>, relay=localhost [127.0.0.1], reject=553 5.1.8 <root@ironfist-droplet>... Domain of sender address root@ironfist-droplet does not existFeb  5 11:06:52 ironfist-droplet sendmail[27722]: v15G6qmc027722: to=root, ctladdr=root (0/0), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=30196, relay=[127.0.0.1] [127.0.0.1], dsn=5.1.8, stat=User unknownFeb  5 11:06:52 ironfist-droplet sm-mta[27724]: v15G6qtl027724: from=<root@ironfist-droplet>, size=196, class=0, nrcpts=0, proto=ESMTP, daemon=MTA-v4, relay=localhost [127.0.0.1]Feb  5 11:06:52 ironfist-droplet sendmail[27722]: v15G6qmc027722: v15G6qmd027722: DSN: User unknownFeb  5 11:06:52 ironfist-droplet sm-mta[27724]: v15G6qtn027724: from=<>, size=2194, class=0, nrcpts=1, msgid=<201702051606.v15G6qmd027722@ironfist-droplet>, proto=ESMTP, daemon=MTA-v4, relay=localhost [127.0.0.1]Feb  5 11:06:52 ironfist-droplet sendmail[27722]: v15G6qmd027722: to=root, delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=31220, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (v15G6qtn027724 Message accepted for delivery)Feb  5 11:06:52 ironfist-droplet sm-mta[27725]: v15G6qtn027724: to=<root@ironfist-droplet>, delay=00:00:00, xdelay=00:00:00, mailer=local, pri=32407, dsn=2.0.0, stat=SentFeb  5 11:06:57 ironfist-droplet sendmail[27730]: v15G6vDO027730: from=root, size=196, class=0, nrcpts=1, msgid=<201702051606.v15G6vDO027730@ironfist-droplet>, relay=root@localhostFeb  5 11:06:57 ironfist-droplet sm-mta[27732]: v15G6vBt027732: ruleset=check_rcpt, arg1=<root@ironfist-droplet>, relay=localhost [127.0.0.1], reject=553 5.1.8 <root@ironfist-droplet>... Domain of sender address root@ironfist-droplet does not existFeb  5 11:06:57 ironfist-droplet sendmail[27730]: v15G6vDO027730: to=root, ctladdr=root (0/0), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=30196, relay=[127.0.0.1] [127.0.0.1], dsn=5.1.8, stat=User unknownFeb  5 11:06:57 ironfist-droplet sm-mta[27732]: v15G6vBt027732: from=<root@ironfist-droplet>, size=196, class=0, nrcpts=0, proto=ESMTP, daemon=MTA-v4, relay=localhost [127.0.0.1]Feb  5 11:06:57 ironfist-droplet sendmail[27730]: v15G6vDO027730: v15G6vDP027730: DSN: User unknownFeb  5 11:06:57 ironfist-droplet sm-mta[27732]: v15G6vBv027732: from=<>, size=2194, class=0, nrcpts=1, msgid=<201702051606.v15G6vDP027730@ironfist-droplet>, proto=ESMTP, daemon=MTA-v4, relay=localhost [127.0.0.1]Feb  5 11:06:57 ironfist-droplet sendmail[27730]: v15G6vDP027730: to=root, delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=31220, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (v15G6vBv027732 Message accepted for delivery)Feb  5 11:06:57 ironfist-droplet sm-mta[27733]: v15G6vBv027732: to=<root@ironfist-droplet>, delay=00:00:00, xdelay=00:00:00, mailer=local, pri=32407, dsn=2.0.0, stat=SentFeb  5 11:08:43 ironfist-droplet sendmail[27745]: v15G8hA4027745: from=root, size=196, class=0, nrcpts=1, msgid=<201702051608.v15G8hA4027745@ironfist-droplet>, relay=root@localhostFeb  5 11:08:43 ironfist-droplet sm-mta[27747]: v15G8hUp027747: ruleset=check_rcpt, arg1=<root@ironfist-droplet>, relay=localhost [127.0.0.1], reject=553 5.1.8 <root@ironfist-droplet>... Domain of sender address root@ironfist-droplet does not existFeb  5 11:08:43 ironfist-droplet sendmail[27745]: v15G8hA4027745: to=root, ctladdr=root (0/0), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=30196, relay=[127.0.0.1] [127.0.0.1], dsn=5.1.8, stat=User unknownFeb  5 11:08:43 ironfist-droplet sm-mta[27747]: v15G8hUp027747: from=<root@ironfist-droplet>, size=196, class=0, nrcpts=0, proto=ESMTP, daemon=MTA-v4, relay=localhost [127.0.0.1]Feb  5 11:08:43 ironfist-droplet sendmail[27745]: v15G8hA4027745: v15G8hA5027745: DSN: User unknownFeb  5 11:08:43 ironfist-droplet sm-mta[27747]: v15G8hUr027747: from=<>, size=2194, class=0, nrcpts=1, msgid=<201702051608.v15G8hA5027745@ironfist-droplet>, proto=ESMTP, daemon=MTA-v4, relay=localhost [127.0.0.1]Feb  5 11:08:43 ironfist-droplet sendmail[27745]: v15G8hA5027745: to=root, delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=31220, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (v15G8hUr027747 Message accepted for delivery)Feb  5 11:08:43 ironfist-droplet sm-mta[27748]: v15G8hUr027747: to=<root@ironfist-droplet>, delay=00:00:00, xdelay=00:00:00, mailer=local, pri=32407, dsn=2.0.0, stat=SentFeb  5 11:09:30 ironfist-droplet sendmail[27772]: v15G9U0s027772: from=root, size=196, class=0, nrcpts=1, msgid=<201702051609.v15G9U0s027772@ironfist-droplet>, relay=root@localhostFeb  5 11:09:30 ironfist-droplet sm-mta[27774]: v15G9UTw027774: ruleset=check_rcpt, arg1=<root@ironfist-droplet>, relay=localhost [127.0.0.1], reject=553 5.1.8 <root@ironfist-droplet>... Domain of sender address root@ironfist-droplet does not existFeb  5 11:09:30 ironfist-droplet sendmail[27772]: v15G9U0s027772: to=root, ctladdr=root (0/0), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=30196, relay=[127.0.0.1] [127.0.0.1], dsn=5.1.8, stat=User unknownFeb  5 11:09:30 ironfist-droplet sm-mta[27774]: v15G9UTw027774: from=<root@ironfist-droplet>, size=196, class=0, nrcpts=0, proto=ESMTP, daemon=MTA-v4, relay=localhost [127.0.0.1]Feb  5 11:09:30 ironfist-droplet sendmail[27772]: v15G9U0s027772: v15G9U0t027772: DSN: User unknownFeb  5 11:09:30 ironfist-droplet sm-mta[27774]: v15G9UU0027774: from=<>, size=2194, class=0, nrcpts=1, msgid=<201702051609.v15G9U0t027772@ironfist-droplet>, proto=ESMTP, daemon=MTA-v4, relay=localhost [127.0.0.1]Feb  5 11:09:30 ironfist-droplet sendmail[27772]: v15G9U0t027772: to=root, delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=31220, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (v15G9UU0027774 Message accepted for delivery)Feb  5 11:09:30 ironfist-droplet sm-mta[27775]: v15G9UU0027774: to=<root@ironfist-droplet>, delay=00:00:00, xdelay=00:00:00, mailer=local, pri=32407, dsn=2.0.0, stat=SentFeb  5 15:34:09 ironfist-droplet sendmail[29166]: v15KY9ME029166: from=root, size=196, class=0, nrcpts=1, msgid=<201702052034.v15KY9ME029166@ironfist-droplet>, relay=root@localhostFeb  5 15:34:09 ironfist-droplet sm-mta[29168]: v15KY9Bg029168: ruleset=check_rcpt, arg1=<root@ironfist-droplet>, relay=localhost [127.0.0.1], reject=553 5.1.8 <root@ironfist-droplet>... Domain of sender address root@ironfist-droplet does not existFeb  5 15:34:09 ironfist-droplet sendmail[29166]: v15KY9ME029166: to=root, ctladdr=root (0/0), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=30196, relay=[127.0.0.1] [127.0.0.1], dsn=5.1.8, stat=User unknownFeb  5 15:34:09 ironfist-droplet sm-mta[29168]: v15KY9Bg029168: from=<root@ironfist-droplet>, size=196, class=0, nrcpts=0, proto=ESMTP, daemon=MTA-v4, relay=localhost [127.0.0.1]Feb  5 15:34:09 ironfist-droplet sendmail[29166]: v15KY9ME029166: v15KY9MF029166: DSN: User unknownFeb  5 15:34:09 ironfist-droplet sm-mta[29168]: v15KY9Bi029168: from=<>, size=2194, class=0, nrcpts=1, msgid=<201702052034.v15KY9MF029166@ironfist-droplet>, proto=ESMTP, daemon=MTA-v4, relay=localhost [127.0.0.1]Feb  5 15:34:09 ironfist-droplet sendmail[29166]: v15KY9MF029166: to=root, delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=31220, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (v15KY9Bi029168 Message accepted for delivery)Feb  5 15:34:09 ironfist-droplet sm-mta[29169]: v15KY9Bi029168: to=<root@ironfist-droplet>, delay=00:00:00, xdelay=00:00:00, mailer=local, pri=32407, dsn=2.0.0, stat=SentFeb  5 15:34:59 ironfist-droplet sendmail[29179]: v15KYxAq029179: from=root, size=196, class=0, nrcpts=1, msgid=<201702052034.v15KYxAq029179@ironfist-droplet>, relay=root@localhostFeb  5 15:34:59 ironfist-droplet sm-mta[29181]: v15KYx21029181: ruleset=check_rcpt, arg1=<root@ironfist-droplet>, relay=localhost [127.0.0.1], reject=553 5.1.8 <root@ironfist-droplet>... Domain of sender address root@ironfist-droplet does not existFeb  5 15:34:59 ironfist-droplet sendmail[29179]: v15KYxAq029179: to=root, ctladdr=root (0/0), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=30196, relay=[127.0.0.1] [127.0.0.1], dsn=5.1.8, stat=User unknownFeb  5 15:34:59 ironfist-droplet sm-mta[29181]: v15KYx21029181: from=<root@ironfist-droplet>, size=196, class=0, nrcpts=0, proto=ESMTP, daemon=MTA-v4, relay=localhost [127.0.0.1]Feb  5 15:34:59 ironfist-droplet sendmail[29179]: v15KYxAq029179: v15KYxAr029179: DSN: User unknownFeb  5 15:34:59 ironfist-droplet sm-mta[29181]: v15KYx23029181: from=<>, size=2194, class=0, nrcpts=1, msgid=<201702052034.v15KYxAr029179@ironfist-droplet>, proto=ESMTP, daemon=MTA-v4, relay=localhost [127.0.0.1]Feb  5 15:34:59 ironfist-droplet sendmail[29179]: v15KYxAr029179: to=root, delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=31220, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (v15KYx23029181 Message accepted for delivery)Feb  5 15:34:59 ironfist-droplet sm-mta[29182]: v15KYx23029181: to=<root@ironfist-droplet>, delay=00:00:00, xdelay=00:00:00, mailer=local, pri=32407, dsn=2.0.0, stat=SentFeb  5 15:35:24 ironfist-droplet sendmail[29189]: v15KZNKB029189: from=root, size=196, class=0, nrcpts=1, msgid=<201702052035.v15KZNKB029189@ironfist-droplet>, relay=root@localhostFeb  5 15:35:24 ironfist-droplet sm-mta[29191]: v15KZOSx029191: ruleset=check_rcpt, arg1=<root@ironfist-droplet>, relay=localhost [127.0.0.1], reject=553 5.1.8 <root@ironfist-droplet>... Domain of sender address root@ironfist-droplet does not existFeb  5 15:35:24 ironfist-droplet sendmail[29189]: v15KZNKB029189: to=root, ctladdr=root (0/0), delay=00:00:01, xdelay=00:00:00, mailer=relay, pri=30196, relay=[127.0.0.1] [127.0.0.1], dsn=5.1.8, stat=User unknownFeb  5 15:35:24 ironfist-droplet sm-mta[29191]: v15KZOSx029191: from=<root@ironfist-droplet>, size=196, class=0, nrcpts=0, proto=ESMTP, daemon=MTA-v4, relay=localhost [127.0.0.1]Feb  5 15:35:24 ironfist-droplet sendmail[29189]: v15KZNKB029189: v15KZNKC029189: DSN: User unknownFeb  5 15:35:24 ironfist-droplet sm-mta[29191]: v15KZOT1029191: from=<>, size=2194, class=0, nrcpts=1, msgid=<201702052035.v15KZNKC029189@ironfist-droplet>, proto=ESMTP, daemon=MTA-v4, relay=localhost [127.0.0.1]Feb  5 15:35:24 ironfist-droplet sendmail[29189]: v15KZNKC029189: to=root, delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=31220, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (v15KZOT1029191 Message accepted for delivery)Feb  5 15:35:24 ironfist-droplet sm-mta[29192]: v15KZOT1029191: to=<root@ironfist-droplet>, delay=00:00:00, xdelay=00:00:00, mailer=local, pri=32407, dsn=2.0.0, stat=SentFeb  5 15:35:34 ironfist-droplet sendmail[29199]: v15KZYoU029199: from=root, size=196, class=0, nrcpts=1, msgid=<201702052035.v15KZYoU029199@ironfist-droplet>, relay=root@localhostFeb  5 15:35:34 ironfist-droplet sm-mta[29201]: v15KZYQ4029201: ruleset=check_rcpt, arg1=<root@ironfist-droplet>, relay=localhost [127.0.0.1], reject=553 5.1.8 <root@ironfist-droplet>... Domain of sender address root@ironfist-droplet does not existFeb  5 15:35:34 ironfist-droplet sendmail[29199]: v15KZYoU029199: to=root, ctladdr=root (0/0), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=30196, relay=[127.0.0.1] [127.0.0.1], dsn=5.1.8, stat=User unknownFeb  5 15:35:34 ironfist-droplet sm-mta[29201]: v15KZYQ4029201: from=<root@ironfist-droplet>, size=196, class=0, nrcpts=0, proto=ESMTP, daemon=MTA-v4, relay=localhost [127.0.0.1]Feb  5 15:35:34 ironfist-droplet sendmail[29199]: v15KZYoU029199: v15KZYoV029199: DSN: User unknownFeb  5 15:35:34 ironfist-droplet sm-mta[29201]: v15KZYQ6029201: from=<>, size=2194, class=0, nrcpts=1, msgid=<201702052035.v15KZYoV029199@ironfist-droplet>, proto=ESMTP, daemon=MTA-v4, relay=localhost [127.0.0.1]Feb  5 15:35:34 ironfist-droplet sendmail[29199]: v15KZYoV029199: to=root, delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=31220, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (v15KZYQ6029201 Message accepted for delivery)Feb  5 15:35:34 ironfist-droplet sm-mta[29202]: v15KZYQ6029201: to=<root@ironfist-droplet>, delay=00:00:00, xdelay=00:00:00, mailer=local, pri=32407, dsn=2.0.0, stat=SentIf anyone finds anything that could be of help in the logs, please don't hesitate to let me know. I'm still doing research and trying to find what might be wrong and going through the logs, however, since I'm not as skilled in this area, all help in any form is appreciated.Mail.err.1 log:Jan 24 23:21:47 ironfist-droplet sendmail[2417]: My unqualified host name (ironfist-droplet) unknown; sleeping for retryJan 24 23:22:47 ironfist-droplet sendmail[2417]: unable to qualify my own domain name (ironfist-droplet) -- using short nameJan 24 23:22:47 ironfist-droplet sm-mta[2486]: My unqualified host name (ironfist-droplet) unknown; sleeping for retryJan 24 23:22:50 ironfist-droplet sm-msp-queue[2491]: My unqualified host name (ironfist-droplet) unknown; sleeping for retryJan 24 23:23:47 ironfist-droplet sm-mta[2486]: unable to qualify my own domain name (ironfist-droplet) -- using short nameJan 24 23:23:50 ironfist-droplet sm-msp-queue[2491]: unable to qualify my own domain name (ironfist-droplet) -- using short nameThank you. 
Sendmail SMTP not working on apache2 server [My unqualified host name (X) unknown]
ubuntu;apache httpd;email;smtp