Connection could not be established with host mail.domain.com [Connection timed out #110]

[humptydumpty]

Sigh. Server died upon activating the firewall.

[girish]

@humptydumpty not sure how the firewall works but maybe when you enable one rule, it blocks all others . So , you have to open port 80 and port 443 as well.

[humptydumpty]

Maybe I should open all of these too (except for "any"). I do use SSH and 53 for the DNS makes sense. IDK about the MYSQL and PGSQL though.

[humptydumpty]

@girish That didn't help. I still can't send the test email in FS. Here's what I have activated in the Hetzner firewall. Server is up though so you're right, it does block all unless specified.

[girish]

@humptydumpty are you using Cloudflare? I can't think of any other reason

[humptydumpty]

For the mail server domain, yes. The mailbox (different domain) is using Bunny. Proxy is off though. CDN acceleration is disabled in Bunny DNS. I didn't change anything at all when this issue started. It's been working fine. I use FS daily. Also, mail is working fine in Roundcube so DNS, ports, wtv are correct. It's FS that's picky, no sending/fetching of mailboxes. Oh, and I have multiple mailboxes using domains on Cloudflare and Bunny. Issue is the same for all. Issue is the same on a fresh FS, so it's not module related either.

Under manage > mail settings > system emails > send test to --- This test email is sent and received fine!

[girish]

@humptydumpty the system email is configured by cloudron itself. You can ignore this (for this problem).

One thing in your screenshot: I noticed now that FS has changed it's TLS options (very nice). You have to choose STARTTLS for port 587. In yours it is none.

[girish]

[humptydumpty]

The docs still say to use none if CR mail and FS are on the same server (which they are for my case). I updated it to TLS, but issue persists. I even restarted the app with no effect.

[girish]

@humptydumpty the docs are a bit outdated since FS has changed the Encryption options. I will fix that once we resolve this... I am out of ideas now though. Can you send us an email to support@cloudron.io with the domain? It must be something very obvious because our FS works.

[humptydumpty]

@girish Sent.

[humptydumpty]

@girish I'm not sure if you got my email as I sent an email (proton email) to my CR email (roundcube) and I didn't receive it. I deleted the Hetzner firewall (as I've had it this whole time) and then sent a new email and then it was received in Roundcube.

[girish]

@humptydumpty thanks.

Just as an update: we found that for some reason, the docker containers (any of them) are unable to reach any port other than port 443/80 using the public IP. From the server itself, all ports of public IP are reachable... Have to debug this further tomorrow.

[Dave Swift]

Any update on this? I'm having the same issue.

[humptydumpty]

This is happening if the mailserver and freescout are on the same server. You can either move FS to another CR or change the mailbox settings (sending/fetching) to what's shown in the screenshots below until a perm fix is released and then you can revert to the previous settings.

SENDING

---

FETCHING

[girish]

Right, the issue here was related to disabling the userland proxy in Docker. This breaks setups where containers in UDN are unable to connect to each other via public IP. Will investigate this coming week for a proper fix. Until then, simply use what @humptydumpty said

[girish]

I pushed a fixed in the firewall for this. It's part of 8.2.3, you have to update Cloudron and hopefully that fixes this.

[bmann]

I am on 8.2.3 on a Hostinger VPS and also having trouble fetching.

This is an old FS that I had stopped and just now turned on again. Previous settings worked (group shared mailbox) -- in that it fetched the IMAP folders and said the connection was working, and the email arrives in snappymail. Tried humptydumpty settings, also "worked", still not fetching.

Sending works fine from FS, from Snappy, etc.

[girish]

Can you try openssl s_client -connect <mailsever>:993 -crlf from web terminal of FS? Does it connect?

[bmann]

@girish said in Connection could not be established with host mail.domain.com [Connection timed out #110]:

openssl s_client -connect <mailsever>:993 -crlf

Since I'm using the localhost settings that HD said, I used this (note host name and alt port):

openssl s_client -connect mail:9393 -crlf

Got this response:

CONNECTED(00000003)
40A74365227F0000:error:0A00010B:SSL routines:ssl3_get_record:wrong version number:../ssl/record/ssl3_record.c:354:
---
no peer certificate available
---
No client certificate CA names sent
---
SSL handshake has read 5 bytes and written 293 bytes
Verification: OK
---
New, (NONE), Cipher is (NONE)
Secure Renegotiation IS NOT supported
Compression: NONE
Expansion: NONE
No ALPN negotiated
Early data was not sent
Verify return code: 0 (ok)
---