Email Loop Detected on 1.15.2

jmoore2017

Hello, I am getting repeated "Email Loop Detected" emails in my logs. Please see below.

Email loop detected
It appears as though is being used as a forwarded or fetched email account and is also being used as a user / system account. Please correct the loop or seek technical assistance.

I have checked that I am not sending any tickets TO my FROM email account and none of my agents or FROM email account have forwarding setup. What is the best way to debug this error to see what exactly is triggering it? My logs are filling up as I see this ever two minutes.

Install info below:
`About this osTicket Installation
Server Information
osTicket Version v1.15.2 (cb6766e) — Up to date
Web Server Software nginx/1.14.2
MySQL Version 10.3.23
PHP Version 7.3.19-1_deb10u1
PHP Extensions
gdlib Used for image manipulation and PDF printing
imap Used for email fetching
xml XML API
xml-dom Used for HTML email processing
json Improves performance creating and processing JSON
mbstring Highly recommended for non western european language content
phar Highly recommended for plugins and language packs
intl Highly recommended for non western european language content
fileinfo Used to detect file types for uploads
zip Used for ticket and task exporting
APCu Improves overall performance
Zend Opcache Improves overall performance
PHP Settings
cgi.fix_pathinfo "1" is recommended if AJAX is not working
date.timezone Setting default timezone is highly recommended
Database Information and Usage
Schema support (localhost)
Schema Signature add628927ee030469f5d3272ebda1e16
Space Used 5.14 MiB
Space for Attachments 1.52 MiB
Timezone EDT (Interpreted as America/New_York)

Installed Language Packs
English (United States)
en_US — include/i18n/en_US`

ntozier

You would have to investigate the accounts on your mail server to see what addresses (or email groups) are forwarding to whom, etc.

jmoore2017

What specific scenario would I be looking for? This is all through GMAIL and there is no forwarding.

I’m really interested in the logic used by osTicket that is used to generate these logs. Why isn’t this documented?

ntozier

The logic is that endless email loops would be bad. So they try to prevent them.

jmoore2017

I understand that but I’m asking for the actual logic used to detect a loop not the justification logic.

I guess I’ll go digging through code...

jmoore2017

Line 893 in osticket/upload/include/class.thread.php:

       // Mail sent by this system will have a predictable message-id
        // If this incoming mail matches the code, then it very likely
        // originated from this system and looped
        $info = Mailer::decodeMessageId($mailinfo['mid']);
        if ($info && $info['loopback']) {
            // This mail was sent by this system. It was received due to
            // some kind of mail delivery loop. It should not be considered
            // a response to an existing thread entry
            if ($ost)
                $ost->log(LOG_ERR, _S('Email loop detected'), sprintf(
                _S('It appears as though &lt;%s&gt; is being used as a forwarded or fetched email account and is also being used as a user / system account. Please correct the loop or seek technical assistance.'),
                $mailinfo['email']),

So it looks like the mail fetcher to the GMAIL account is finding a message with a particular "MID" and triggering the log.

My hypotheses is that since I don't delete messages from the inbox some old email is triggering this. Let's see if I can dig deeper...

jmoore2017

It's 4:27PM and I haven't received a single log notification since I enable email deletion from the GMAIL inbox at 4:05PM:

This fixed it. I would have found this way faster if the "MID" lookup feature was actually documented and didn't require the user to dig in the code to figure out how it works.