smtpd | A Lightweight High Performance ESMTP email server

I followed this document and I can get what I want. The most importance thing is that the command does not copy the generated files into the pyhton 3.9.4 folder automatically. You have to copy them manually.

1) first download the project under this link and then unpack the file.

Run these under cmd:

So, turns out, when I updated my certificate locations when I changed the method of acquiring them (certbot vs acme.sh), I got a typo in one of the filenames. /etc/dovecot/conf.d/10-ssl.conf was correct and so was /etc/postfix/main.cf, but /etc/postfix/vmail_ssl.map had a typo which I didn't see previously - and so was throwing a certificate error.

I found it! In /etc/postfix/helo_access.pcre, there was this regex pattern:

/.*\.co$/ DISCARD Unauthorized-2015-240

which matched the message in the logs:

Helo command Unauthorized-2015-240

So I added regex to allow that specific domain:

/.*o1.ptr3680.wellable.co$/ OK

then reloaded Postfix and the emails were received upon trying again.

Based on your shown samples, could you please try following. Written and tested in GNU awk.

I'm not too familiar with Xcode, but the problem as you describe it clearly seems to be the communication between the Xcode application and your Postfix SMTP server. I would try the following:

1. Obtain Xcode logs.

   • The post I found below states this can be done by (a) using Console.app, (b) starting Xcode via Terminal.app, or (c) checking for Diagnostic Reports
   • https://stackoverflow.com/a/46674772/15238212

2. Obtain Postfix logs.

   • Again, these can be found in Console.app as they should be created by ASL (i.e. macOS's syslog)
   • Additionally, you could specify your own log file as stated in the documentation on the Postfix website: http://www.postfix.org/MAILLOG_README.html

Hopefully by doing this you be able to see if your configured mail updates are making it out of Xcode and reaching your Postfix server.

Okay, so apparently I was sent on a wild goose chase.

The compounding factor is because I have suppressed ALL exceptions in these lines:

SASL (Simple Authentication and Security Layer) is a framework for authentication. SSL (TLS) is a framework of protocols that provide secure communications over a network. SSL (TLS) can provide authentication via client certificates. I am not aware of an email client (MUA) that supports certificate authentication.

The original design of SMTP allowed for email to arrive from anywhere and be forwarded anywhere. In the old days, we called email servers Store and Forward servers. However, today with the high prevalence of Spam and Phishing, allowing anyone to transfer email to an SMTP server is a bad idea. Blindly forwarding email (open relay) is also a bad idea.

Postfix uses SASL to provide authentication for mail clients (MUAs). This can be as simple as a username/password or one of many authentication services such as LDAP or Active Directory. SASL is the software that handles authentication on behalf of Postfix.

There are many providers of SASL software. The choice depends on your network design, authentication sources, design goals, etc. If your usernames are stored in Azure Active Directory, then you would select SASL software that supports Azure Active Directory. Another example is using MySQL to store your users. Once you design your network, the choice becomes fairly easy usually.

Postfix also implements other forms of authorization to determine if it should accept email from other SMTP servers. This is where network affinity (are you on an authorized network or IP address), Reverse DNS, SPF, DMARC, DKIM, etc are used.

SSL can be used to encrypt communications between SMTP servers and between the email client and the SMTP server. This provides secrecy but not authorization.

I didn't focus before that I run pabot with 8 processes while django app was started with 2 celery workers. As soon as I increased celery workers to 4 it worked. Not sure though if this is the actually cause but it made sense to me as well as it worked.

celery -A server -c ${CELERY_CONCURRENCY:-2} worker

You need to quote the filter expression, to tell the shell to pass it as a literal argument to the log command rather than trying to parse it as shell syntax (which is what causes the error).