SOLVED Outbound SMTP not working on my External Relay

[subtlecourage]

Hello all! I am trying to setup my server to house my employees, however, an issue I am running into is in my email logs I get the error below

I set up my SMTP outbound server according to the docs here -

I have a green circle next to my domain in my Domains subsection under my Email section

My email logs look like this

My SMTP status says

And the outbound settings are fully filled out.

I have verified that my proper port number is 465.

And Finally, I verified I am using the right username and password as well.

What am I doing wrong?

[fbartels]

Hi @subtlecourage,

• is that all the same domain for these error messages?
• when you manually look up the mx records of these domains, do they exist?
• if you do a portscan on one of the mx hosts, does something listen on port 25?

[subtlecourage]

@fbartels

@fbartels said in Outbound SMTP not working on my External Relay:

Hi @subtlecourage,

• is that all the same domain for these error messages?

Yes, the domain name is the same across the board

• when you manually look up the mx records of these domains, do they exist?

• if you do a portscan on one of the mx hosts, does something listen on port 25?
  This one, I dont quite understand.

I am able to send and receive email via my domain through the hosted provider
Cloudron is set up to do outbound only

[girish]

@subtlecourage said in Outbound SMTP not working on my External Relay:

I have verified that my proper port number is 465.

Usually port 465 is the (obsolete) TLS port. Most providers use port 587 as STARTTLS. Does your provider have port 587? If so, can you try that instead?

That said, the email relay setup should actually try to make a connection to check if the connection works and clearly you managed to save the settings, so somehow port 465 works.

[girish]

@subtlecourage You can also do this:

• Open the mail log window (It's in the email view in the bottom)
• Then, click the plane button next to the domain. This sends a test email.

Can you paste the logs here or to https://paste.cloudron.io ? Thanks,

[subtlecourage]

@girish When I try that port (587) I get

I am using Fastmail

[subtlecourage]

@girish I have DM'ed you the logs

[girish]

@subtlecourage thanks! I should have been clearer but I wanted the raw logs. There is a button in the top right that says Logs. Can you give me those logs ? They contain info on why the server is unable to connect to MX.

[subtlecourage]

@girish Sent it your way!

[subtlecourage]

@subtlecourage Let me know what you think of those logs

[girish]

@subtlecourage I didn't find the time today, but will take a look tomorrow.

[girish]

@subtlecourage So, the connections are failing with "socket timeout waiting on connect" . Can you SSH into your server and check if "telnet smtp.xxx.com 465" works? If it doesn't , then it could either be the VPS provider is blocking it OR that the smtp provider is blocking it. I tried to connect from my server(s) and it connects fine. So, it's probably a VPS thing. Are you on linode by any chance? I recently learnt they block outbound port 465 and 587 by default on new accounts.

[subtlecourage]

@girish No, I am using hetzner

I am getting a -bash: telnet: command not found

Ok, just kidding.

I installed it.

I got this

:~$ telnet smtp.fastmail.com 465
Trying 66.111.4.140...
Connected to smtp.fastmail.com.
Escape character is '^]'.
Connection closed by foreign host.

[girish]

@subtlecourage Ah ok, so the smtp connection works well enough. Strange then, did you figure this one out already?

[subtlecourage]

@girish said in Outbound SMTP not working on my External Relay:

@subtlecourage Ah ok, so the smtp connection works well enough. Strange then, did you figure this one out already?

Sadly, no.
I keep getting these messages
[outbound] Ongoing connection failed to 66.111.4.140:465 : socket timeout waiting on connect

That is to fastmails servers

Is there any DNS setting that could cause that?

[subtlecourage]

@subtlecourage

I cant get any welcome emails to send, nor password reset emails. This is neutering my install.

[girish]

@subtlecourage Not sure what is going on here. Are you able to contact us on support@cloudron.io, so we can debug on the server?

[girish]

@subtlecourage my bad, I should have noticed. The issue here is that Cloudron's relay system only supports STARTTLS. This means that you have to use port 587 in your relay. Port 465 is pure "TLS" (as opposed to port 587 which is opportunistic TLS). Can you try with port 587? If that doesn't work, let me debug further.

[subtlecourage]

@girish said in Outbound SMTP not working on my External Relay:

@subtlecourage my bad, I should have noticed. The issue here is that Cloudron's relay system only supports STARTTLS. This means that you have to use port 587 in your relay. Port 465 is pure "TLS" (as opposed to port 587 which is opportunistic TLS). Can you try with port 587? If that doesn't work, let me debug further.

Hah, that solved it.

Thank you.

[subtlecourage]

@girish

It is doing something weird though.

It says it should be coming from noreplay@domain.com, but instead it is coming from imanalias@domain.com

Any ideas?

[girish]

@subtlecourage said in Outbound SMTP not working on my External Relay:

It says it should be coming from noreplay@domain.com, but instead it is coming from imanalias@domain.com

Can you clarify what you mean by "it says"? Is there some error/warning somewhere? Also, I assume that you have put a custom domain in fastmail and also fastmail is able to relay mail as any email address i.e <anything>@domain.com ?