Wordpress smtp can't connect mail server

unexjourney

Hi;
I use Wordpress SMTP extension to connect mailcow-dockerized server but it can’t connect mailcow.Also, I tried on thunderbird and everything work. I get error on SMTP extensions;

`2024-09-16 09:34:48 Connection: opening to ssl://mail.xyz.com:465, timeout=30, options=array()

2024-09-16 09:34:49 Connection failed. Error #2: stream_socket_client(): Peer certificate CN=cp.xyz.com' did not match expected CN=mail.xyz.com’ [/home/abcde/public_html/wp-includes/PHPMailer/SMTP.php line 409]

2024-09-16 09:34:49 Connection failed. Error #2: stream_socket_client(): Failed to enable crypto [/home/abcde/public_html/wp-includes/PHPMailer/SMTP.php line 409]

2024-09-16 09:34:49 Connection failed. Error #2: stream_socket_client(): Unable to connect to ssl://mail.xyz:465 (Unknown error) [/home/abcd/public_html/wp-includes/PHPMailer/SMTP.php line 409]

2024-09-16 09:34:49 SMTP ERROR: Failed to connect to server: (0)

SMTP Error: Could not connect to SMTP host. Failed to connect to server
`

ETNyx

Your problem is in SSL certificate. You are trying to connect mail.xyz.com using ssl on port 465, WP is able to connect but this server have SSL certificate issued for cp.xyz.com.

1) It is wrong server? You have issue in your DNS
2) You have some problem in SSL, Are you using Mailcow integrated ACME? (did you set SKIP_LETS_ENCRYPT=y)?

unexjourney

ETNyx
1-Server is right and the mail works on local smtp client.
2-I installed mailcow docker integrated how can i check SSL and rebuild mail.xyz.com

ETNyx

Take a look into docs, this page have more information about SSL

unexjourney

ETNyx I checked everything looks okay. I rebuild certificates. When i choose “Allow Non-Secure SSL Certificates ” section on wordpress plugin mail sends. How can fix it? Use my own certificate?

ETNyx

So you are using included ACME (Let’s Encrypt), right? In this case, in your mailcow.conf you have MAILCOW_HOSTNAME, it is “cp.xyz.com” right? And that is your FDQN of your Mailcow instance, right? So set up your WP to connect to this FDQN instead.

If you must use non-FDQN domain, you can add this domain to ADDITIONAL_SERVER_NAMES that is describe in docs. This way you can add alternative domain to your FDQN.

unexjourney

ETNyx
My Wordpress configuration:
mail server:mail.xyz.com
smtp port 465
SSL activated

Mailcow Config File;
MAILCOW_HOSTNAME=mail.xyz.com
ADDITIONAL_SAN=cp.xyz.com
ADDITIONAL_SERVER_NAMES=cp.xyz.com
SKIP_LETS_ENCRYPT=n

I tried re-create certificate but when i tried this prompt
“docker compose logs –tail=200 acme-mailcow”
created sucessfuly but says;
Certificates were successfully renewed where required, sleeping another day

DocFraggle

unexjourney Mailcow Config File;
MAILCOW_HOSTNAME=mail.xyz.com
ADDITIONAL_SAN=cp.xyz.com
ADDITIONAL_SERVER_NAMES=cp.xyz.com
SKIP_LETS_ENCRYPT=n

In your post above you had cp.refonstechnology.com configured previously?

Is it possible that you have a DNS problem on your client? Because the client is connecting to mail.refonstechnology.com and an EXIM server is answering? Did you modify your hosts file or have a special NAT rule in place?

[unknown] 2024-09-17 07:29:22 SERVER -> CLIENT: 220-cp.refonstechnology.com ESMTP Exim 4.97.1 #2 Tue, 17 Sep 2024 10:29:22 +0300 220-We do not authorize the use of this system to transport unsolicited, 220 and/or bulk e-mail.

unexjourney

I checked everywhere and don’t use cp.xyz.com domain. I don’t know, wordpress plugin where it found it

DocFraggle

Without knowing your real FQDN we can’t really help and check your certificate…

You can have a look at the details of your certificate here: https://www.ssl.org/

unexjourney

My SSL report result;
https://www.ssl.org/report/mail.refonstechnology.com

our mailcow domain mail.refonstechnology.com

Actual wordpress smtp report
`Server:
OpenSSL: OpenSSL 1.1.1k FIPS 25 Mar 2021

Debug:
E-posta Kaynağı: Easy WP SMTP
Mailer: Diğer SMTP
SMTP Error: Could not connect to SMTP host. Failed to connect to serverSMTP server error: Failed to connect to server

SMTP Debug:
2024-09-17 07:29:22 Connection: opening to mail.refonstechnology.com:587, timeout=30, options=array()

2024-09-17 07:29:22 Connection: opened

2024-09-17 07:29:22 SERVER -> CLIENT: 220-cp.refonstechnology.com ESMTP Exim 4.97.1 #2 Tue, 17 Sep 2024 10:29:22 +0300 220-We do not authorize the use of this system to transport unsolicited, 220 and/or bulk e-mail.

2024-09-17 07:29:22 CLIENT -> SERVER: EHLO garajupservice.com

2024-09-17 07:29:22 SERVER -> CLIENT: 250-cp.refonstechnology.com Hello garajupservice.com [78.135.106.158]250-SIZE 52428800250-8BITMIME250-PIPELINING250-PIPECONNECT250-AUTH PLAIN LOGIN250-STARTTLS250 HELP

2024-09-17 07:29:22 CLIENT -> SERVER: STARTTLS

2024-09-17 07:29:22 SERVER -> CLIENT: 220 TLS go ahead

2024-09-17 07:29:22 Connection failed. Error #2: stream_socket_enable_crypto(): Peer certificate CN=cp.refonstechnology.com' did not match expected CN=mail.refonstechnology.com’ [/home/garajupservice/public_html/wp-includes/PHPMailer/SMTP.php line 488]

SMTP Error: Could not connect to SMTP host. Connection failed. stream_socket_enable_crypto(): Peer certificate CN=cp.refonstechnology.com' did not match expected CN=mail.refonstechnology.com’

2024-09-17 07:29:22 CLIENT -> SERVER: QUIT

2024-09-17 07:29:22

2024-09-17 07:29:22 Connection: closed

SMTP Error: Could not connect to SMTP host. Connection failed. stream_socket_enable_crypto(): Peer certificate CN=cp.refonstechnology.com' did not match expected CN=mail.refonstechnology.com’`

DocFraggle

unexjourney SMTP Debug:
2024-09-17 07:29:22 Connection: opening to mail.refonstechnology.com:587, timeout=30, options=array()

2024-09-17 07:29:22 Connection: opened

2024-09-17 07:29:22 SERVER -> CLIENT: 220-cp.refonstechnology.com ESMTP Exim 4.97.1 #2 Tue, 17 Sep 2024 10:29:22 +0300 220-We do not authorize the use of this system to transport unsolicited, 220 and/or bulk e-mail.

Once again: you seem to be reaching an Exim mailserver, not your mailcow. Do you have an interal DNS server in place which has an old/wrong DNS entry for mail.refonstechnology.com which points to the IP address of this Exim server?

DocFraggle

ok, so what’s your SAN then? cp.refonstechnology.com? I don’t see that as SAN on the certificate and it doesn’t resolve via DNS

unexjourney

The main problem is cp.refonstechnology.com. The adress don’t use anywhere.I can’t understand this situation.
My mailcow config;
MAILCOW_HOSTNAME=mail.refonstechnology.com
ADDITIONAL_SERVER_NAMES=
ADDITIONAL_SAN=

unexjourney

I tried SAN cp.refonstechnology.com but not work.Get authentication error on SMTP client

ETNyx

If you want to use SAN (Subject Alternative Name) you need to make correct DNS record, otherwise you will not be able to make certificate for it (acme/let’s encrypt will not be able).

You do not have A and/or AAAA for cp.refonstechnology.com.

dig @1.1.1.1 A cp.refonstechnology.com

; <<>> DiG 9.20.1 <<>> @1.1.1.1 A cp.refonstechnology.com
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 10767
;; flags: qr rd ra ad; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;cp.refonstechnology.com.	IN	A

;; AUTHORITY SECTION:
refonstechnology.com.	1800	IN	SOA	launch1.spaceship.net. support.spaceship.com. 1726492539 43200 3600 604800 3600

;; Query time: 93 msec
;; SERVER: 1.1.1.1#53(1.1.1.1) (UDP)
;; WHEN: Tue Sep 17 13:51:40 CEST 2024
;; MSG SIZE  rcvd: 127

dig @1.1.1.1 AAAA cp.refonstechnology.com

; <<>> DiG 9.20.1 <<>> @1.1.1.1 AAAA cp.refonstechnology.com
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 49547
;; flags: qr rd ra ad; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;cp.refonstechnology.com.	IN	AAAA

;; AUTHORITY SECTION:
refonstechnology.com.	1800	IN	SOA	launch1.spaceship.net. support.spaceship.com. 1726492539 43200 3600 604800 3600

;; Query time: 40 msec
;; SERVER: 1.1.1.1#53(1.1.1.1) (UDP)
;; WHEN: Tue Sep 17 13:52:25 CEST 2024
;; MSG SIZE  rcvd: 127

unexjourney

Problem solved.Thank you. The main reason is cpanel always redirect smtp request itself. We closed the SMTP restriction settings.