Quick question about email

[nebulon]

@abargel can you check if you can connect to the smtp port in question 587 ? Not sure how your tunnel is setup and works, but if IMAP (receiving) works, then I suspect this is some special firewall setting when using the tunnel on either the tunnel side or your OpenVPN client configs.

[abargel]

@nebulon Well, Evolution "sending mail" is set up to port 465 with TLS over a dedicated port. The instructions say 587 or 465 and I don't know the difference...
I'm not sure what is a tunnel not how it is setup...
My OpenVPN client is the Cloudron app as well, just on a separate server (which does not allow SMTP OUT, by the way) so a separate Cloudron account as well.
Hope you can make sense of this, I realize that there are gaping holes in what I understand and therefore can tell you!

[abargel]

@abargel *nor how it is setup

[girish]

@abargel said in Quick question about email:

The instructions say 587 or 465 and I don't know the difference

Port 587 is STARTTLS. Port 465 is TLS.

Can you try "telnet my.xxx.net 465" on your PC after connecting to VPN? Does it connect ? This could also be an IPv6 related issue, but let's see what telnet says.

[abargel]

@girish telnet says "Unable to connect to host: connection refused".
Without the VPN, telnet connects.
It's the same from both my computers, on which I use VPN from the same server.

[girish]

@abargel Can you try "telnet -4 my.xxx.com 465" just to make sure it's IPv4 ? I wonder if this might be a client side VPN issue - what OS is your client?

[abargel]

@girish Same results. I'm on Ubuntu (different versions) on both computers.

[girish]

@abargel Do port 587 (starttls) , 443 (https) , 80 (http) work? Or do all fail?

[abargel]

@girish 80 and 443 work, 587 doesn't

[girish]

@abargel mmm. Just to double check, can you check if all traffic is indeed going via the VPN ? (curl https://ipv4.api.cloudron.io/api/v1/helper/public_ip)

Next step to debug after confirming above:

• Open Web terminal in VPN app.
• Run the telnet commands on different ports. I suspect things are failing here too. If so, then there is some routing issue.

[abargel]

@girish The curl command gives this (first with VPN off, then VPN on) The second IP is indeed that of my VPS where OpenVPN is.

minipc@minipc-iPC45:~$ curl https://ipv4.api.cloudron.io/api/v1/helper/public_ip
{
  "ip": "91.163.111.16"
}minipc@minipc-iPC45:~$ curl https://ipv4.api.cloudron.io/api/v1/helper/public_p
{ 
  "ip": "91.199.223.67"

Running the telnet command in the Web terminal gives the same results as before.

On my end, I tried checking the open ports on that VPS with "ss -tunlp" and it seems that ports 465 and 587 are not open, but 80 and 443 are. I tried opening the port with "nc -lk 465" command, but nothing happens. In doubt, I opened a ticket with the VPS provider asking if they can open port 465. Waiting for answer.

Other thought was, do I need to enable email in Cloudron that is on that VPS, so that the ports for email are open?

[abargel]

@girish Oh, never mind, it was an SMTP OUT block by the VPS provider... I didn't think that it would apply to running email from another server through OpenVPN on this one...
Sorry for taking your time with this, and thanks again.