I monitored the network while trying to send mails in case it gives clues about the problem, and I think I figured it out.
Here's a successful mail send from CI3:
Code:
No Time Source Destination Protocol Length Info
----------------------------------------------------------------------------------------------------
14 0.510596 ___.___.___.___ ___.___.___.___ TCP 66 63640 → 587 [SYN] Seq=0 Win=64240 Len=0 MSS=1460 ...
15 0.551575 ___.___.___.___ ___.___.___.___ TCP 66 587 → 63640 [SYN, ACK] Seq=0 Ack=1 Win=8192 Len= ...
16 0.551652 ___.___.___.___ ___.___.___.___ TCP 54 63640 → 587 [ACK] Seq=1 Ack=1 Win=66048 Len=0
21 0.588550 ___.___.___.___ ___.___.___.___ SMTP 145 S: 220 ___.___.___ ESMTP ___ Corporate Mail Serv ...
22 0.589183 ___.___.___.___ ___.___.___.___ SMTP 70 C: EHLO localhost
23 0.628545 ___.___.___.___ ___.___.___.___ SMTP 307 S: 250-___.___.___ Hello localhost [___.___.___. ...
24 0.628808 ___.___.___.___ ___.___.___.___ SMTP 66 C: AUTH LOGIN
27 0.668526 ___.___.___.___ ___.___.___.___ SMTP 72 S: 334 VXNnrh56bWU6
28 0.668638 ___.___.___.___ ___.___.___.___ SMTP 88 C: User: ___
30 0.697355 ___.___.___.___ ___.___.___.___ SMTP 72 S: 334 UGFzcxsf5mQ6
31 0.697514 ___.___.___.___ ___.___.___.___ SMTP 68 C: Pass: ___
33 0.749191 ___.___.___.___ ___.___.___.___ SMTP 91 S: 235 2.0.0 Authentication successful
34 0.749385 ___.___.___.___ ___.___.___.___ SMTP 90 C: MAIL FROM:<___@___.___>
35 0.788907 ___.___.___.___ ___.___.___.___ SMTP 103 S: 250 2.1.0 <___@___.___>... Sender ok
36 0.789059 ___.___.___.___ ___.___.___.___ SMTP 89 C: RCPT TO:<___@___.___>
37 0.828452 ___.___.___.___ ___.___.___.___ SMTP 107 S: 250 2.1.5 <___@___.___>... Recipient ok
38 0.828783 ___.___.___.___ ___.___.___.___ SMTP 60 C: DATA
43 0.857081 ___.___.___.___ ___.___.___.___ SMTP 104 S: 354 Enter mail, end with "." on a line by its ...
44 0.857203 ___.___.___.___ ___.___.___.___ SMTP 506 C: DATA fragment, 452 bytes
47 0.950460 ___.___.___.___ ___.___.___.___ TCP 54 587 → 63640 [ACK] Seq=570 Ack=606 Win=130560 Len ...
48 0.950516 ___.___.___.___ ___.___.___.___ SMTP/IMF 57 from: <___@___.___>, subject: =?UTF-8?Q?Hey?=,
51 0.999937 ___.___.___.___ ___.___.___.___ SMTP 149 S: 250 2.6.0 450 bytes received in 00:00:00; Mes ...
52 1.000092 ___.___.___.___ ___.___.___.___ SMTP 60 C: QUIT
53 1.049809 ___.___.___.___ ___.___.___.___ SMTP 102 S: 221 2.0.0 ___.___.___ closing connection
and the problematic one from the CI4:
Code:
No Time Source Destination Protocol Length Info
----------------------------------------------------------------------------------------------------
87 3.444594 ___.___.___.___ ___.___.___.___ TCP 66 64054 → 587 [SYN] Seq=0 Win=64240 Len=0 MSS=1460 ...
92 3.477140 ___.___.___.___ ___.___.___.___ TCP 66 587 → 64054 [SYN, ACK] Seq=0 Ack=1 Win=8192 Len= ...
93 3.477217 ___.___.___.___ ___.___.___.___ TCP 54 64054 → 587 [ACK] Seq=1 Ack=1 Win=66048 Len=0
94 3.506342 ___.___.___.___ ___.___.___.___ SMTP 145 S: 220 ___.___.___ ESMTP ___ Corporate Mail Serv ...
95 3.506506 ___.___.___.___ ___.___.___.___ SMTP 70 C: EHLO localhost
98 3.535388 ___.___.___.___ ___.___.___.___ SMTP 307 S: 250-___.___.___ Hello localhost [___.___.___. ...
99 3.535588 ___.___.___.___ ___.___.___.___ SMTP 64 C: STARTTLS
101 3.562844 ___.___.___.___ ___.___.___.___ SMTP 84 S: 220 2.0.0 Ready to start TLS
103 3.599593 ___.___.___.___ ___.___.___.___ TLSv1 571 Client Hello
104 3.656124 ___.___.___.___ ___.___.___.___ TLSv1 959 Server Hello, Certificate, Server Hello Done
105 3.656588 ___.___.___.___ ___.___.___.___ TLSv1 61 Alert (Level: Fatal, Description: Unknown CA)
110 3.691253 ___.___.___.___ ___.___.___.___ TCP 54 587 → 64054 [FIN, ACK] Seq=1280 Ack=551 Win=1305 ...
111 3.691470 ___.___.___.___ ___.___.___.___ TCP 54 64054 → 587 [ACK] Seq=551 Ack=1281 Win=64768 Len ...
112 3.698468 ___.___.___.___ ___.___.___.___ SMTP 60 C: QUIT
113 3.702807 ___.___.___.___ ___.___.___.___ TCP 54 64054 → 587 [FIN, ACK] Seq=557 Ack=1281 Win=6476 ...
Notice the difference. CI3 does not start a TLS, but the mail debugger says otherwise.
Upon further investigation, I noticed that in the email class
$smtp_crypto is set to "" by default. So the
TLS check in
_smtp_connect() is never run.
However, in CI4,
$SMTPCrypto is set to "tls" by default, so the
TLS check is always run unless it's changed.
Now, to solve the problem, all I have to do is set
$SMTPCrypto to
"". The final state of the code:
PHP Code:
$email = \Config\Services::email();
$config = [
"protocol" => "smtp",
"SMTPHost" => "___.___.___",
"SMTPPort" => 587,
"SMTPCrypto" => "", // now it's the same as CI3
"SMTPUser" => "___@___.___",
"SMTPPass" => "___",
"newline" => "\r\n",
];
$email->initialize($config);
$email->setFrom($config["SMTPUser"]);
$email->setTo("___@___.___");
$email->setSubject("Hey");
$email->setMessage("Howdy?");
$email->send(false);
echo $email->printDebugger();
and voila!
Quote:220 ______.___ ESMTP ___ Corporate Mail Service; Sun, 23 May 2021 16:58:23 +0300
hello: 250-______.___ Hello localhost [___.___.___.___], pleased to meet you.
250-ENHANCEDSTATUSCODES
250-SIZE
250-EXPN
250-ETRN
250-ATRN
250-DSN
250-CHECKPOINT
250-8BITMIME
250-AUTH PLAIN LOGIN DIGEST-MD5 CRAM-MD5 GSSAPI
250-STARTTLS
250 HELP
from: 250 2.1.0 ... Sender ok
to: 250 2.1.5 ... Recipient ok
data: 354 Enter mail, end with "." on a line by itself
250 2.6.0 466 bytes received in 00:00:00; Message id 202105231658233843 accepted for delivery
quit: 221 2.0.0 ______.___ closing connection
Your message has been successfully sent using the following protocol: smtp
Date: Sun, 23 May 2021 08:58:21 -0500
From: <___@___.___>
Return-Path: <___@___.___>
To: ___@___.___
Subject: =?UTF-8?Q?Hey?=
Reply-To: <___@___.___>
User-Agent: CodeIgniter
X-Sender: ___@___.___
X-Mailer: CodeIgniter
X-Priority: 3 (Normal)
Message-ID: <60aa5f7d96a295.26287360@___.___>
Mime-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Howdy?
While I managed to pinpoint the source of the problem and make it work, I still need a word from the team. Is it safe to set
SMTPCrypto to an empty string? If not, that's how the email class works in CI3. Why the change?
If I shouldn't be setting
SMTPCrypto to an empty string, how do I solve the problem? Especially on the localhost?
One solution that comes to mind is that modifying
SMTPCrypto depending on the environment or something else.
