Having trouble with Bounces not working after moving Mailwizz to Ubuntu 18.04


We have been using Mailwizz for years...we are not novices. Usually it performs nicely. We send 250,000 emails each day. We moved our operation from AWS on Ubuntu 16.04 to Digital Ocean on Ubuntu 18.04 over a month ago. Twice it has stopped recording bounces. There is no apparent problem when I look at the bounce servers. They are always active in MW. But last week I found 64,000 unprocessed emails in the bounce address after MW stopped showing bounces.. I deleted those and Mailwizz started processing bounces again.

It was working well until 2 days ago when again no bounces for ANY deliver server. Nothing was changed in that time.

Now I see 31,000 unprocessed emails in the bounce server.

Have you ever seen anything like this before?

SO I followed instructions at https://forum.mailwizz.com/threads/...untu-bionic-18-04-3-lts-with-php-7-2-24.6396/

And now https://email.causeaction.com/phpinfo.php shows that PCNTL is enabled.

But still there are no bounces showing up in MW from today's sends.

They were showing up fine for several days, form the same Bounce mailbox...and then just stopped.

Our Return-Path in the header is richard@causeaction.com.

Today that mailbox has over 49,000 emails and Mailwizz is not processing them.

The Mailwizz server is Ubuntu 18.04 with Nginx and PHP 7.2. It has 6 vcpu and 16 GB of memory. The Monitor graphs show only moederate usage of CPU and Memory. There is 300 GB of free disk space.

And lastly, after 2 days, the bounces from June 1 finally showed up .Why the long delay? What is wrong with Mailwizz?
But they haven't been working since.

UPDATE: The bounces from June 2 just showed up....and today is June 4.

Also I noticed that in the email headers I see this: X-Wccc-Campaign-Uid: hk353fdsl6f82
When the online help says I should see this: X-Mw-Campaign-Uid: tf833t6s9z842

I do not rememeber customising the file apps/common/config/main-custom.php nor do I see any code for a custom header prefix like:

'email.custom.header.prefix' => 'X-Whatever-',

Before I go deleting the bounce emails from the bounce server again, do you have any suggestions for us?

Thank you


Message-ID: <2c0963c16d77b04c41e4eb2678e0c33f@causeaction.com>
Date: Wed, 03 Jun 2020 07:38:56 +0000
Subject: Inform. Consider. Engage.
From: CauseACTION <rich@causeaction.com>
Reply-To: CauseACTION <rich@causeaction.com>
To: "chevy195@excite.com" <chevy195@excite.com>
MIME-Version: 1.0
Content-Type: multipart/alternative;
X-Wccc-Tracking-Did: 0
X-Wccc-Subscriber-Uid: mb45688p4o85e
X-Wccc-Mailer: SwiftMailer - 5.4.x
X-Wccc-EBS: https://email.causeaction.com/index.php/lists/block-address
X-Wccc-Delivery-Sid: 32
X-Wccc-Customer-Uid: oe776dlpxy494
X-Wccc-Customer-Gid: 1
X-Wccc-Campaign-Uid: hk353fdsl6f82
X-Sender: richard@causeaction.com
X-Report-Abuse: Please report abuse for this campaign here:
X-Receiver: chevy195@excite.com
Precedence: bulk
List-Unsubscribe: <https://email.causeaction.com/index...direct?source=email-client-unsubscribe-button>,
<mailto:rich@causeaction.com?subject=Campaign-Uid:hk353fdsl6f82 /
Subscriber-Uid:mb45688p4o85e - Unsubscribe request&body=Please unsubscribe
do you have any suggestions for us?
Follow https://kb.mailwizz.com/articles/debug-send-campaigns-command/ but except send-campaigns, use bounce-handler.
That should tell you all you need to know.

Also I noticed that in the email headers I see this: X-Wccc-Campaign-Uid: hk353fdsl6f82
When the online help says I should see this: X-Mw-Campaign-Uid: tf833t6s9z842
We're not using X-Mw-... for years now. Now, each install will get it's own unique prefix.
Hello. There are 64000 unprocessed emails in the bounce server. Here is the debug of bounce-handler I ran to file. It processed only about 100 emails. Why? All the others are not showing up in Mailwizz. They still sit on the bounce server.
It shows Started processing server ID 20...but when I look at Mailwizz servers it doesn't show me Server ID. How do I even know if it is processing the correct Bounce address?

Where is the clue I need to determine what is happening? I don't see it.
And here is a screenshot of MW not showing bounces for up to 3 days. It is now June 6 and we see only bounces from June 3 and previous.
We are warming some new IPs and need to be vigilant about bounces and complaints.
AlsoMailwizzBounces3DaysLate.jpgMailwizzBounceServer.jpg here is the screen for Bounce Handler

Remember, it was running fine on its new server and then for no apparent reason stopped showing bounces in the MW interface.
And then 3 days later some bounces show up. After years of using Mailwizz I am stumped as to what could be the problem.
Thanks for the help.


  • mwbounce.txt
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Also I am monitoring the bounce address richard@causeaction.com in my Outlook. Here is a screen shot to show you that bounce emails are indeed entering that mailbox but are not showing up in the campaigns screen. it's 10:24 my time and we see bounce emails from a few minutes ago. But still not showing in MW.MailwizzBounceAddressHas Emails.jpg

And here is email on the actual Mail Server itself so you can see that Outlook is not deleting emails as it pulls them. as you can see I am really trying hard to get this fixed.

MailwizzBouncesOnThe MailServer.jpg
Well I deleted all the unprocessed bounce emails at the server. The next morning Mailwizz was again processing and displaying bounces. I don't know how long it will continue to process bounces, as this temporary "fix" worked last time too. But only for a few days and then Mailwizz again began to fail. I cannot find any clues in the --verbose run of bounce-handler. And we have to manually record the bounce emails that MW did not process.
I wish there was some way to monitor when MW is at its point of failure so we can see what is being output at that time. Should I juts run the CRON job to File so at least I will have something to work with?
I have attached a screen shot of the Campaign screen showing that bounces are again being recorded. However the Bounce percentage seems to be off by a factor of 100. There are only 500 emails in each of those campaigns. We are warming IPs and need to mitigate the ISPs. So we very much need to deal with bounces and complaints.
MW Bounces day after deletion.jpg
@Papapooch - By default mailwizz looks in your email box for campaigns that are at most 3 days old, we can't look up for years as processing those might take forever. So what i think it happens is that mailwizz gets a large volume of bounces and while processing them, which takes time, and since the time passes, then older messages are simply ignored because of the 3 days rule.
You can adjust those 3 days if you wish, from backend > settings > cron, in the "Settings for processing bounce servers" section, set the "Days back" setting to more than 3 days, this will make mailwizz look back more days, so processing more bounces.