Looking to send an email to another MIAB user

1

I have an issue where no more emails are being received by the other parties. I opened a thread here Postfix error dsn=4.3.0 - #2 by Mg344

It affects various providers, some of which I am pretty sure that they are not using Gmail in the background.

I understand that error is usually something to do with the receiving party, but I doubt that 10+ different email providers have an issue all of a sudden.

I have all green checkmarks in my MIAB dashboard. And sending within my own MIAB works.

So, as a test I thought, how about sending an email to another known MIAB user? I do not know any, so would someone be willing to share their email (via private message), so I can send a test message to them and see if the error persists?

2

  1. Check your server admin → System / Status Checks. There should be zero errors or warnings.

  2. Try sending FROM gmail/outlook/whatever TO your server, and wait for any bounce/error replies. Those services can be picky about who can send to them, but they’re usually happen to send to anyone.

  • If you can get an email from (say) gmail, then see if you can send a reply to the sender.
  1. I’ve found the following webites useful, though they do assume a level of IT knowledge:
3

Thank you for your reply.

I have all green check-marks, no errors or warnings.

I can receive email just fine on various domains and accounts on this MIAB.

MXToolbox reports blackllsted on Uceprotectl3 which my MIAB was on that for at least 24 months now.

DKIMValidator does not receive my email.

Internet.nl points at some TLS and ciphers that should be phased out. Further a DANE scheme is missing. Finally, the one that stands out to me a bit (not sure if it is the main issue though) is that there is no route authorisation (RPKI). All my secondary NS have it I will look into that further, although the MIAB dashboard makes no reference to it.

4

Out of curiosity, see if your box can connect to the gmail servers. Try:
nc 142.251.163.27 25
nc 2607:f8b0:4004:c1b::1a 25

For each, you should get a reply like:
220 mx.google.com ESMTP 6a1803df08f44-6d88de63cd3si32667756d6.378 - gsmtp
(then clobber the nc with ^C).

Those IP addresses are for gmail. If you can get an nc connection and a reply, then your box can see the gmail server. If not, there’s your problem …

PS. Unless you’ve completely disabled either IPv6 or IPv4 (!), I think you’ll need to be able to get a connection on both, because MIAB could use either when trying to send.

5

Thank you for your help.

I do indeed get these replies, as you indicated:

miab@box:~$ nc 142.251.163.27 25
220 mx.google.com ESMTP ada2fe7eead31-4af593dc497si2966486137.731 - gsmtp
^C
miab@box:~$ nc 2607:f8b0:4004:c1b::1a 25
220 mx.google.com ESMTP d75a77b69052e-466c40547d1si89757491cf.21 - gsmtp
^C

I have both IPv4 and v6 enabled. That is the thing, this box ran fine for some two years, without me modifying anything from the stock script and all of a sudden 10+ providers can not receive email without any indication? It is strange.

6

In the meantime I was able to send an email to another MIAB user (thanks again!), but the error remains:

Action: delayed
Status: 4.3.0

:truck:

7

Time to get your hands dirty … so to speak. Have a good look through the log files and work out what’s going wrong.

The mail mail log is /var/log/mail.log

You can make the system generate more detail by editing /etc/postfix/master.cf and adding -v to the line (near the top) like:
smtp inet n - y - - smtpd
becomes
smtp inet n - y - - smtpd -v
then run the command postfix reload to enable the updated config.

Adding more v’s (like -vvv) provides even more log detail.

The logs will show you (up to quite a lot of detail) exactly the connections made, replies received, etc. You’ll learn more about emal than you wanted to know, but that’s part of running your own server :slight_smile:

1 Like
8

@andrew
Mg344 send me a message. All seems fine just a delay of 6 hours.

It seems that he is sending via relay
@Mg344
Type in terminal when you send a message and see the reply.
cat /var/log/mail.log | grep "postfix/smtp" | grep -P 'status='

Your relay by the message I recived is via https://mxroute.com/

Login there maybe there is a setup for delayed sending? Or change your relay provider. MailJet, MailGun Sendgrid all offer free service.
Otherwise just send via your own box if Outbound Port 25 is not blocked

By the way I see from your SPF that you have an account with AnyMXRelay
Maybe @alento could be of some help here as he maintans that relay?

9

Again, thank you for helping out.

It is true, I forgot, I have the Anydomain service to prevent being blocked or my emails going straight to spam.

I do not mind looking through logs and trying to figure out things, I understood that from the main MIAB setup instructions.

Going through the logs showed:

warning: smtp_tls_wrappermode requires "smtp_tls_security_level = encrypt" (or stronger)

In /etc/postfix/main.cf I found smtp_tls_security_level=encrypt was commented out. I removed the # on that line.

Following that, the log showed

warning: /etc/postfix/main.cf, line 38: overriding earlier entry: smtp_tls_security_level=dane

So i commented that option out.

Emails are now being received instantly again. However, if this was the right thing to do with regards to MIAB configuration, I do not know. I guess, I have to be vigilant when doing a future update.

1 Like
10

main.cf is not modified with updates. No worries!

1 Like
11

Hi @Mg344

I definitely would like to look further into this, though I have not received any reports of similar issues from anyone else.

Do you know when this issue began exactly?

I am rarely here on this forum these days unfortunately, but please feel free to DM me and I will get a notification. Thanks @vele for the mention.

12

Actually, I have seen it happen before, when v55 was released.

As a matter of fact, this exact same situation. Though it is not the MiaB update that did this, but rather a Postfix update, I do believe.

13

Aha. That will explain the update. Since it is a major postfix update :slight_smile: Good to know.

1 Like