Articles I've written for customers on IT issues.
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\documentclass[11pt]{article}
%Gummi|065|=)
\title{\textbf{}}
\usepackage{graphicx}
\usepackage{caption }
\author{Steak Electronics}
%\date{06/4/19}
\begin{document}
%\maketitle
\textbf{Email Stuff}
\vspace{0.2in}
%\textbf{Todo}
\section{Manual Email Server Interaction}
How to send emails manually. This is essential for troubleshooting automated email systems.
\section{Basics}
\begin{verbatim}
openssl s_client -debug -starttls smtp -crlf -connect smtp.emailprovider.com:465
then continue with
EHLO hostname
AUTH
etc...
\end{verbatim}
Here's an example:
\begin{verbatim}
Compression: NONE
Expansion: NONE
No ALPN negotiated
SSL-Session:
Protocol : TLSv1.2
Cipher : ECDHE-RSA-AES128-GCM-SHA256
Session-ID: 480E968D62206D936801683C3BB12679DCB5CEDB0B20F4C3C2EB9DC97A54FAF4
Session-ID-ctx:
Master-Key: BAB3C9AD7E209D2A979A621731BCB6A0B4368EEE03E2B99CF884D2671E2D62A1A365EEB50FC881CA2E4FD666082027BA
Key-Arg : None
PSK identity: None
PSK identity hint: None
SRP username: None
TLS session ticket lifetime hint: 300 (seconds)
TLS session ticket:
0000 - 26 e3 0c d9 a7 0e b1 88-52 ce 35 aa a0 8d bd 40 &.......R.5....@
0010 - 0c 39 e4 60 04 59 06 bb-b2 7e 35 f9 56 36 d1 46 .9.`.Y...~5.V6.F
0020 - d2 8c 48 29 44 fa 9f 2b-cd af fc 9a 68 b0 b8 63 ..H)D..+....h..c
0030 - 35 06 cd ba 67 57 bf c4-84 19 5a 05 fd a7 62 51 5...gW....Z...bQ
0040 - 1c 63 d7 b0 b4 ce 62 9f-66 13 7b 4c 74 54 86 fa .c....b.f.{LtT..
0050 - 3b 31 e1 e1 bd 19 29 e8-76 c2 6c 45 db 1d 32 50 ;1....).v.lE..2P
0060 - 60 63 ec 38 a3 e5 de 26-d6 27 c6 26 60 09 1a 59 `c.8...&.'.&`..Y
0070 - 59 e9 97 b4 07 9f 6c fc-46 cb 9e 0b 40 57 8f 71 Y.....l.F...@W.q
0080 - 20 98 54 06 38 42 47 c1-e6 fd 74 92 dc 11 a5 97 .T.8BG...t.....
0090 - 5d 81 7e 0b 66 b7 8e aa-c0 61 48 0c 90 84 ac 2d ].~.f....aH....-
Start Time: 1590893833
Timeout : 300 (sec)
Verify return code: 0 (ok)
---
250 PIPELINING
EHLO localhost
write to 0x1c0dd20 [0x1c17853] (45 bytes => 45 (0x2D))
0000 - 17 03 03 00 28 2a 65 16-62 f5 2c 8c e5 d9 f2 ef ....(*e.b.,.....
0010 - bb 8a ac 3a 6a dc db 32-79 56 7f 86 90 2e ed 44 ...:j..2yV.....D
0020 - 6e 6a ea 12 64 bb f8 1e-95 7e 63 16 c5 nj..d....~c..
read from 0x1c0dd20 [0x1c13303] (5 bytes => 5 (0x5))
0000 - 17 03 03 00 a7 .....
read from 0x1c0dd20 [0x1c13308] (167 bytes => 167 (0xA7))
0000 - 80 ae b0 b8 00 a2 d6 6b-47 42 2c 5d 30 1c 04 bd .......kGB,]0...
0010 - 5c bb 84 61 20 5a 2e 0d-c5 79 28 a9 21 d6 ad 1b \..a Z...y(.!...
0020 - 99 e5 fc da a1 fb da bc-70 9e 9b ac 5a e1 0f 8e ........p...Z...
0030 - bb c8 6d cb 2e 27 af 9b-4a 6a e8 17 69 31 63 14 ..m..'..Jj..i1c.
0040 - 24 68 d7 6b cc a7 dc 24-7c d6 4b fa 2a 3e 38 61 $h.k...$|.K.*>8a
0050 - 58 57 4d e8 1c e7 66 3c-22 0f 07 62 42 14 e7 78 XWM...f<"..bB..x
0060 - 86 8a 6c 6f 8f 79 06 f6-dc 33 b5 e9 ec db b8 b4 ..lo.y...3......
0070 - 0e 7d d7 08 17 cd 4d b3-ac 16 79 08 87 df 31 95 .}....M...y...1.
0080 - 03 8d 9e 8c 25 09 ca 38-d0 be ee 45 38 d8 c4 a5 ....%..8...E8...
0090 - c3 90 44 23 5d e7 9b 1b-c0 40 d2 cc 40 c5 4a e4 ..D#]....@..@.J.
00a0 - 25 38 8b 05 2f b2 33 %8../.3
250-www192.vfemail.net
250-8BITMIME
250-AUTH PLAIN
250-BURL imap
250-CHUNKING
250-ENHANCEDSTATUSCODES
250-SIZE 78643200
250 PIPELINING
\end{verbatim}
Here you might enter at the prompt
\\
\\
AUTH LOGIN
But that will fail:
\begin{verbatim}
AUTH LOGIN
write to 0x1c0dd20 [0x1c17853] (41 bytes => 41 (0x29))
0000 - 17 03 03 00 24 2a 65 16-62 f5 2c 8c e6 59 01 74 ....$*e.b.,..Y.t
0010 - 10 99 f5 d2 e6 75 88 d3-b9 58 0e 92 78 fc f1 ad .....u...X..x...
0020 - c6 aa 50 2a 6c f4 cf e5-dd ..P*l....
read from 0x1c0dd20 [0x1c13303] (5 bytes => 5 (0x5))
0000 - 17 03 03 00 3a ....:
read from 0x1c0dd20 [0x1c13308] (58 bytes => 58 (0x3A))
0000 - 80 ae b0 b8 00 a2 d6 6c-bf e5 f8 3d 5a 39 93 2b .......l...=Z9.+
0010 - f8 a2 12 03 0f 0f 5c a3-95 0a 6c b6 d9 fa 3d 09 ......\...l...=.
0020 - 73 f7 5c 26 8c 41 aa cf-87 0f 65 61 52 7d ec f7 s.\&.A....eaR}..
0030 - 4a fe cd a4 f8 3e be 48-a3 92 J....>.H..
504 5.5.4 Authentication failed.
\end{verbatim}
If you look at the EHLO, it responds with what auth it supports. In this case, AUTH PLAIN. So it accepts plain text passwords (over an encrypted session of course).
Unfortunately, ssmtp (which I'm using) doesn't support plain. from ssmtp manual:
Specifies mechanism for SMTP authentication. (Only LOGIN and CRAM-MD5)
If you instead type AUTH PLAIN or auth plain, it will respond with 334. It is then waiting for credentials.
\begin{verbatim}
ref: https://wiki.zoneminder.com/SMS_Notifications
\end{verbatim}
You can also compare logs in /var/log/mail.log
Here's a working example:
\begin{verbatim}
Jun 16 01:01:02 server sSMTP[19958]: Creating SSL connection to host
Jun 16 01:01:02 server sSMTP[19958]: SSL connection using DHE_RSA_AES_256_CBC_SHA1
Jun 16 01:01:04 server sSMTP[19958]: Sent mail for .com (221 2.0.0 Bye) uid=0 username=root outbytes=91617
Jun 16 01:01:04 server sSMTP[19978]: Creating SSL connection to host
Jun 16 01:01:05 server sSMTP[19978]: SSL connection using DHE_RSA_AES_256_CBC_SHA1
Jun 16 01:01:06 server sSMTP[19978]: Sent mail for .com (221 2.0.0 Bye) uid=0 username=root outbytes=93751
Jun 18 13:30:31 server sSMTP[18220]: Creating SSL connection to host
Jun 18 13:30:32 server sSMTP[18220]: 220 smtp.mxes.net ESMTP Postfix 03
Jun 18 13:30:32 server sSMTP[18220]: EHLO s.com
Jun 18 13:30:32 server sSMTP[18220]: 250 CHUNKING
Jun 18 13:30:32 server sSMTP[18220]: STARTTLS
Jun 18 13:30:32 server sSMTP[18220]: 220 2.0.0 Ready to start TLS
Jun 18 13:30:32 server sSMTP[18220]: SSL connection using DHE_RSA_AES_256_CBC_SHA1
Jun 18 13:30:32 server sSMTP[18220]: EHLO s.com
Jun 18 13:30:32 server sSMTP[18220]: 250 CHUNKING
Jun 18 13:30:32 server sSMTP[18220]: AUTH LOGIN
Jun 18 13:30:32 server sSMTP[18220]: 334 lslslsls
Jun 18 13:30:32 server sSMTP[18220]: somethuing
Jun 18 13:30:32 server sSMTP[18220]: 334 something else6
Jun 18 13:30:32 server sSMTP[18220]: somehashedstuff
Jun 18 13:30:32 server sSMTP[18220]: 235 2.7.0 Authentication successful
Jun 18 13:30:32 server sSMTP[18220]: MAIL FROM:<person@some.com>
Jun 18 13:30:32 server sSMTP[18220]: 250 2.1.0 Ok
Jun 18 13:30:32 server sSMTP[18220]: RCPT TO:<fgdfg>
Jun 18 13:30:33 server sSMTP[18220]: 250 2.1.5 Ok
Jun 18 13:30:33 server sSMTP[18220]: DATA
Jun 18 13:30:33 server sSMTP[18220]: 354 End data with <CR><LF>.<CR><LF>
Jun 18 13:30:33 server sSMTP[18220]: Received: by .com (sSMTP sendmail emulation); Thu, 18 Jun 2020 13:30:30 -0400
Jun 18 13:30:33 server sSMTP[18220]: From: "C" <c@com>
Jun 18 13:30:33 server sSMTP[18220]: Date: Thu, 18 Jun 2020 13:30:30 -0400
Jun 18 13:30:33 server sSMTP[18220]: To: j
Jun 18 13:30:33 server sSMTP[18220]: Subject: My email check
Jun 18 13:30:33 server sSMTP[18220]:
Jun 18 13:30:33 server sSMTP[18220]: Hello, World
Jun 18 13:30:34 server sSMTP[18220]: .
Jun 18 13:30:34 server sSMTP[18220]: 250 2.0.0 Ok: queued as 3B1D6759AF
Jun 18 13:30:34 server sSMTP[18220]: QUIT
Jun 18 13:30:34 server sSMTP[18220]: 221 2.0.0 Bye
Jun 18 13:30:34 server sSMTP[18220]: Sent mail for c (221 2.0.0 Bye) uid=1000 username=c outbytes=439
\end{verbatim}
Here is another non working one.
\begin{verbatim}
Jun 18 17:35:46 zmctankhome sSMTP[22488]: Set MailHub="smtp.mxes.net"
Jun 18 17:35:46 zmctankhome sSMTP[22488]: via SMTP Port Number="587"
Jun 18 17:35:47 zmctankhome sSMTP[22488]: Creating SSL connection to host
Jun 18 17:35:47 zmctankhome sSMTP[22488]: 220 smtp.mxes.net ESMTP Postfix 03
Jun 18 17:35:47 zmctankhome sSMTP[22488]: EHLO .com
Jun 18 17:35:47 zmctankhome sSMTP[22488]: 250 CHUNKING
Jun 18 17:35:47 zmctankhome sSMTP[22488]: STARTTLS
Jun 18 17:35:47 zmctankhome sSMTP[22488]: 220 2.0.0 Ready to start TLS
Jun 18 17:35:48 zmctankhome sSMTP[22488]: SSL connection using ECDHE_RSA_AES_256_GCM_SHA384
Jun 18 17:35:48 zmctankhome sSMTP[22488]: EHLO .com
Jun 18 17:35:48 zmctankhome sSMTP[22488]:
Jun 18 17:35:48 zmctankhome sSMTP[22488]: (.com)
\end{verbatim}
Notice the TLS / SSL encryption is different. That can be a deal breaker. Ouch. Otherwise both are Debian (one is 9, the other 10).
\end{document}