Campaign Emails not being sent to app/spool/default

Your software
My Mautic version is: 2.15.1
My PHP version is: 7.0.33

Your problem
My problem is:
We use PHP to send emails.
When we launch a campaign email and send it to a segment we can see that the emails are sent if we look in the campaign and/or email stats, BUT the actual outgoing emails are not being generated and added to the app/spool/default folder on our server, so no emails are being send.
This used to work in the past but now all of the sudden this no longer works.

Do you have any suggestions on how to solve this?

These errors are showing in the log:
[2020-01-13 16:14:00] mautic.ERROR: [MAIL ERROR] Sending failed for one or more recipients

Steps I have tried to fix the problem:
We have created a new campaign and a new email and tried again -> same result

Does anyone have any suggestions?
We need to push out a large campaign.

Also just noticed that sending a test mail does not work, same error:
[MAIL ERROR] Sending failed for one or more recipients

Please help

Is there nobody who can help us with this? we are pretty desperate by now…


I came across your post as I just had my app/spool/default blow up because of specific reasons. Not sure I can help.

Do you have your Cron Jobs setup correctly ?

Have you tried testing with another ESP, maybe setup a SendGrid account (free) and put the API key in, and run a test campaign. Try and narrow down where the problem is, if this works, you know it might be php mail that is the problem.

I would suggest the slack channel as well for some help

Hi Mike

Thank you for your feedback

Yes the cronjobs are setup correctly and they are still working (adding contacts to segments and campaigns and triggering etc) I can see the contacts being added to a campaign and also see them being added to the email (they show as Sent), Thing is that the emails don’t go to the spool/default folder anymore.

We have our own dedicated server and nothing has changed (except that 2019 is now 2020 :slight_smile: )

I also posted this question on the slack channel but did not get any feedback there (except from slackbot telling me to go here to get support :slight_smile: )

I already started a sendgrid account but am waiting for my CNAME changes to be picked up by them to white label my account.

Do youperhaps know a good guide for integrating sendgrid?


Integration with SendGrid should be pretty simple. It is usually instantaneous with the sender authentication, then all you need to do is create an API key in SendGrid, copy this into email settings in mautic and choose SendGrid API. I would also do link branding.

My feeling is it is not going to make much difference if mails are not being put in default/spool… have you checked permissions on these directories ?

An alternative (but tedious workaround) would be to do a sql dump of the database, fire up a new instance of a server, install a fresh version of mautic and then import the DB.

Let me know how things go & good luck!


with sendgrid do you still have to send emails to spool/default or can you send the emails with Send immediately?

The reason why email queuing is not working might be because the permissions of your app/spool/default path might be incorrect - causing the queue files to not be generated. Can you check that the directory is owned by the web server user (e.g. www-data or apache) and the same for the Mautic path overall?

With SendGrid, you can use the “send immediately” option. Usually queuing is used if you need to throttle the speed of email sending by limiting the batch size - due to host and/or SMTP server limitations.

Queuing is more common if one if managing their own SMTP server using the “Custom SMTP Server” option in Mautic. SendGrid, and other 3rd party email gateways should have their own logic in place to control the sending speed of their customers (i.e. you).

great thx, just started a first mini campaign with around 1000 subscribers to see how well that goes with sendgrid set to SMTP and Send immediately