Mailcow-dockerized: Sender-dependent transports ERROR -- Relay with Amazon SES not working

[pbdco]

Hi, my dockerized Mailcow is working fine to RECEIVE emails, but when I set up the Sender-dependent transport (Relay) with AWS SES, this error shows up when I run the test tool:

No MX records for email-smtp.sa-east-1.amazonaws.com were found in DNS, skipping and using hostname as next-hop.
Connection: opening to email-smtp.sa-east-1.amazonaws.com:25, timeout=10, options=array (
    ↪ 'ssl' =>
    ↪ array (
    ↪ 'verify_peer' => false,
    ↪ 'verify_peer_name' => false,
    ↪ 'allow_self_signed' => true,
    ↪ ),
)
    ↪ Connection failed. Error #2: stream_socket_client(): unable to connect to email-smtp.sa-east-1.amazonaws.com:25 (Operation timed out) [/web/inc/lib/vendor/phpmailer/phpmailer/src/SMTP.php line 344]
    ↪ SMTP ERROR: Failed to connect to server: Operation timed out (110)
    ↪ SMTP connect() failed. https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting

Things to consider:

• Outside Mailcow, my Amazon SES SMTP credentials work 100% -for example sending with Thunderbird- with 9.9/10 deliverability rating.
• The hostname and sender I'm using to test are checked and validated on AWS SES control panel.
• Despite the error message, I tried to send an email from SOGo anyways (using the relay config for my host), but nothing happens (no email nor error messages..)
• There are no firewalls or any third party app blocking my connections.
• Mailcow is working on a standalone server with a fresh Ubuntu 18.04
• Also tried with ports: email-smtp.sa-east-1.amazonaws.com:25, 465 and 587 -- same output.
• My docker-compose ports are as default.

[andryyy]

Issue template...

Where is it hosted?

Am 12.09.2020 um 19:18 schrieb pbdco [e-mail]:


Hi, my dockerized Mailcow is working fine to RECEIVE emails, but when it comes to setting up the Sender-dependent transport (Relay) with AWS SES, I run the test tool and this error shows up:

No MX records for email-smtp.sa-east-1.amazonaws.com were found in DNS, skipping and using hostname as next-hop.
Connection: opening to email-smtp.sa-east-1.amazonaws.com:25, timeout=10, options=array (
↪ 'ssl' =>
↪ array (
↪ 'verify_peer' => false,
↪ 'verify_peer_name' => false,
↪ 'allow_self_signed' => true,
↪ ),
)
↪ Connection failed. Error #2: stream_socket_client(): unable to connect to email-smtp.sa-east-1.amazonaws.com:25 (Operation timed out) [/web/inc/lib/vendor/phpmailer/phpmailer/src/SMTP.php line 344]
↪ SMTP ERROR: Failed to connect to server: Operation timed out (110)
↪ SMTP connect() failed. https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting
Things to consider:

Outside Mailcow, my Amazon SES SMTP credentials work 100% -for example sending with Thunderbird-.
The hostname and sender I'm using to test are checked and validated on AWS SES control panel.
Despite the error message, I tried to send an email from SOGo anyways (using the relay config for my host), but nothing happens (no email nor error messages..)
There are no firewalls or any third party app blocking my connections.
Mailcow is working on a standalone server with a fresh Ubuntu 18.04
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[pbdco]

Hosted at Linode

[pbdco]

| Question | Answer |
| --- | --- |
| My operating system | Ubuntu 18.04 |
| Is Apparmor, SELinux or similar active? | NO |
| Virtualization technlogy (KVM, VMware, Xen, etc - LXC and OpenVZ are not supported | KVM |
| Server/VM specifications (Memory, CPU Cores) | 4gb RAM 4 CPU |
| Docker Version (docker version) | Docker version 19.03.12, build 48a66213fe |
| Docker-Compose Version (docker-compose version) | docker-compose version 1.27.0, build 980ec85b |
| Reverse proxy (custom solution) | NO |

• Output of git diff origin/master, any other changes to the code? NO
• All third-party firewalls and custom iptables rules are unsupported. NO Firewalls or third parties iptables, etc.
• DNS problems? Please run docker exec -it $(docker ps -qf name=acme-mailcow) dig +short stackoverflow.com @172.22.1.254 (set the IP accordingly, if you changed the internal mailcow network) and post the output. -- No dns problems --

Output:
151.101.193.69
151.101.1.69
151.101.129.69
151.101.65.69

docker-compose logs : HERE --> https://pastebin.com/wz1n683W

[pbdco]

I can notice in docker logs (postfix dockerID) this repeating output:

Sep 12 14:07:16 mail postfix/smtp[678]: connect to email-smtp.sa-east-1.amazonaws.com[18.231.10.133]:25: Connection timed out

[andryyy]

https://www.linode.com/blog/linode/a-new-policy-to-help-fight-spam/

They block port 25 outbound by default.

[pbdco]

https://www.linode.com/blog/linode/a-new-policy-to-help-fight-spam/

They block port 25 outbound by default.

No workaround? I've tried putting the hostname ports as :465 and :587 ... same output

[MAGICCC]

Read the link @andryyy gave you? Everything is explained there, even how to ask for unblock

[Adorfer]

template not used, answer not read. support ticket. closed

[pbdco]

Hi @andryyy @MAGICCC @Adorfer

Indeed the problem was because my provider blocks the 25, 465 and 587 ports as default. I've sent them a ticket with my request and the problem has been solved.

Everything is working 100% now and I am very happy for having chosen such a nice piece of email client. The performance, and UI/UX are amazing.

Congratulations for your great work and keep it up with such amazing project. Thank you very much for sharing it with the world.

Regards.