<![CDATA[Email SMTP: Connection Closed]]>CR Dashboard > Email > All domains are "red" after the migration. It looks like I can receive emails in Roundcube, but Freescout isn't receiving and sending from my SMTP relay isn't working at all.

I made a new SMTP user at Mailgun and tried re-saving and I get the "connection closed" error.

ea17d66f-1873-41c8-a2a3-c8ec7d1034ff-image.png

78b00c60-26c0-43ea-a1c6-0ecb124bff0b-image.png

I checked online tools for A records, MX records, etc. and I can see the new IP reflected in all reports. I set up the rDNS on the server for both, IPv4 and IPv6 addresses.

This is a new Hetzner server. Is there anything I need to do, like open ports, etc.?

Edit: It looks like port 110 and 143 are closed. Port 25 is open.

]]>https://forum.cloudron.io/topic/12112/email-smtp-connection-closedRSS for NodeMon, 13 Jul 2026 12:37:39 GMTTue, 16 Jul 2024 16:04:59 GMT60<![CDATA[Reply to Email SMTP: Connection Closed on Wed, 17 Jul 2024 11:44:45 GMT]]>I enabled Dynamic DNS in Cloudron. Then, I turned off the VPS, deleted its IP's (ipv4 and ipv6) and reassigned new ones. Manually updated DNS record of my. to point to the new domain and it came up in 2 mins. Resynced DNS and it looks like the SMTP issue is fixed.

]]>https://forum.cloudron.io/post/91495https://forum.cloudron.io/post/91495Wed, 17 Jul 2024 11:44:45 GMT<![CDATA[Reply to Email SMTP: Connection Closed on Wed, 17 Jul 2024 10:52:29 GMT]]>I received a reply from Hetzner support. I barely had any sleep during the past few days because of this migration so, I'm not entirely sure if I'm reading this right. Maybe I'm dreaming. But, here goes:

Dear Client

Thank you for your request.

Unfortunately, some GeoIP databases incorrectly locate some of our IPs in Iran. We cannot influence these databases.

If this leads to issues for you, please create a Snapshot of the server with the incorrect IP location. Then create a new server with this Snapshot. You can then delete the server with the incorrect IP location.

Mit freundlichen Grüßen / Kind regards

WTF. I signed up for a vDedi server in Ashburn, US. I'm gonna get my a55 probed by the US gov now. Thanks Hetzner.

]]>https://forum.cloudron.io/post/91492https://forum.cloudron.io/post/91492Wed, 17 Jul 2024 10:52:29 GMT<![CDATA[Reply to Email SMTP: Connection Closed on Tue, 16 Jul 2024 22:32:25 GMT]]>Asked ChatGPT for command to test via SSH. Here are the results:

telnet smtp.mydomain.com 587 >> Trying valid-hetzner-server-ip... Connected to smtp.mydomain.com.

nc -vz smtp.mydomain.com 587 >> Connection to smtp.mydomain.com (correct-server-ip) 587 port [tcp/submission] succeeded!

nslookup smtp.mydomain.com >>

Connection to smtp.mydomain.com (correct-server-ip) 587 port [tcp/submission] succeeded!

Server:         127.0.0.53
Address:        127.0.0.53#53

Non-authoritative answer:
Name:   smtp.mydomain.com (masked)
Address: my-server-ip (masked)
]]>https://forum.cloudron.io/post/91463https://forum.cloudron.io/post/91463Tue, 16 Jul 2024 22:32:25 GMT<![CDATA[Reply to Email SMTP: Connection Closed on Tue, 16 Jul 2024 21:45:07 GMT]]>@matix131997 no, I didn’t block anything in the Hetzner firewall. I did try to open port 25 and then disabled that rule but the email/smtp issue was there beforehand as it’s what prompted me to try to open the port only to be told that port 25 isn’t needed for smtp.

]]>https://forum.cloudron.io/post/91462https://forum.cloudron.io/post/91462Tue, 16 Jul 2024 21:45:07 GMT<![CDATA[Reply to Email SMTP: Connection Closed on Tue, 16 Jul 2024 21:22:29 GMT]]>Generally Hetzner does not block outgoing ports except 25 for new customers until the next month, sometimes after two months after payment of the invoice. But blocked ports of other there is no possibility well unless you have set in the external firewall ?

]]>https://forum.cloudron.io/post/91461https://forum.cloudron.io/post/91461Tue, 16 Jul 2024 21:22:29 GMT<![CDATA[Reply to Email SMTP: Connection Closed on Tue, 16 Jul 2024 18:45:16 GMT]]>Noted. I'm guessing this will take till tomorrow at least if Hetzner's support is in Germany.

]]>https://forum.cloudron.io/post/91444https://forum.cloudron.io/post/91444Tue, 16 Jul 2024 18:45:16 GMT<![CDATA[Reply to Email SMTP: Connection Closed on Tue, 16 Jul 2024 18:42:54 GMT]]>@humptydumpty issue is outbound port and not inbound port

]]>https://forum.cloudron.io/post/91442https://forum.cloudron.io/post/91442Tue, 16 Jul 2024 18:42:54 GMT<![CDATA[Reply to Email SMTP: Connection Closed on Tue, 16 Jul 2024 18:37:26 GMT]]>Still waiting on Hetzner support, but I ran a port test and it looks like 587 is open.

image.png

]]>https://forum.cloudron.io/post/91441https://forum.cloudron.io/post/91441Tue, 16 Jul 2024 18:37:26 GMT<![CDATA[Reply to Email SMTP: Connection Closed on Tue, 16 Jul 2024 18:37:36 GMT]]>Thanks Joseph. I emailed Hetzner and will report back.

]]>https://forum.cloudron.io/post/91436https://forum.cloudron.io/post/91436Tue, 16 Jul 2024 18:37:36 GMT<![CDATA[Reply to Email SMTP: Connection Closed on Tue, 16 Jul 2024 16:55:07 GMT]]>@humptydumpty right, that's the bug ... Your server provider for some inexplicable reason has closed outbound port 587. You have to ask their support to open it.

]]>https://forum.cloudron.io/post/91432https://forum.cloudron.io/post/91432Tue, 16 Jul 2024 16:55:07 GMT<![CDATA[Reply to Email SMTP: Connection Closed on Tue, 16 Jul 2024 16:53:44 GMT]]>@joseph this is the result of the swak command

=== Trying smtp.mailgun.org:587...
=== Connected to smtp.mailgun.org.
*** Remote host closed connection unexpectedly.
]]>https://forum.cloudron.io/post/91430https://forum.cloudron.io/post/91430Tue, 16 Jul 2024 16:53:44 GMT<![CDATA[Reply to Email SMTP: Connection Closed on Tue, 16 Jul 2024 16:47:13 GMT]]>https://documentation.mailgun.com/docs/mailgun/user-manual/sending-messages/#send-via-smtp has a example as well

]]>https://forum.cloudron.io/post/91428https://forum.cloudron.io/post/91428Tue, 16 Jul 2024 16:47:13 GMT<![CDATA[Reply to Email SMTP: Connection Closed on Tue, 16 Jul 2024 16:46:14 GMT]]>Maybe try testing using swaks.

swaks -server smtp.mailgun.org:587 -tls --auth-user username --auth-password password --to toaddress@domain.com --from no-reply@cloudrondomain.com
]]>https://forum.cloudron.io/post/91427https://forum.cloudron.io/post/91427Tue, 16 Jul 2024 16:46:14 GMT<![CDATA[Reply to Email SMTP: Connection Closed on Tue, 16 Jul 2024 16:42:29 GMT]]>My SMTP connections are working for the same domains on my two other Cloudrons (home servers), just not on this new Hetzner VPS that I migrated yesterday.

]]>https://forum.cloudron.io/post/91425https://forum.cloudron.io/post/91425Tue, 16 Jul 2024 16:42:29 GMT<![CDATA[Reply to Email SMTP: Connection Closed on Tue, 16 Jul 2024 16:40:46 GMT]]>@joseph That's what I'm using and have used successfully before the migration. I haven't changed anything really.

4f765fa9-d113-4664-ab3d-e81f4fb68113-image.png

]]>https://forum.cloudron.io/post/91424https://forum.cloudron.io/post/91424Tue, 16 Jul 2024 16:40:46 GMT<![CDATA[Reply to Email SMTP: Connection Closed on Tue, 16 Jul 2024 16:39:28 GMT]]>@humptydumpty you have to configure relay to use port 587 (STARTTLS) . Port 25 is not meant for relaying email. Neither are 110 and 143.

]]>https://forum.cloudron.io/post/91423https://forum.cloudron.io/post/91423Tue, 16 Jul 2024 16:39:28 GMT