mail queue doesn't process

I send segment email and mautic says they are sent, but emails do not get delivered. I look and see them stacked in queue:

ll /home/xxxx/public_html/app/spool/default/
-rw-r–r-- 1 xxxxxxxxxx xxxxxxxxxx 20261 Jul 18 19:34 g7Wb99oZBV.message
-rw-r–r-- 1 xxxxxxxxxx xxxxxxxxxx 20263 Jul 18 19:34 HfuQay11tm.message
-rw-r–r-- 1 xxxxxxxxxx xxxxxxxxxx 20268 Jul 18 19:34 KFVA6z7BPc.message
-rw-r–r-- 1 xxxxxxxxxx xxxxxxxxxx 84172 Jul 18 19:48 PuID7CaFX9.message

what specific cron job needs to be set to process this email queue ?

also where can I find cron error logs? I am not finding any applicable errors in
/home/xxxxx/public_html/app/logs/mautic_prod-2018-07-18.php

The email test of the segment email template works fine

BTW here is the crontab file
3,18,33,48 * * * * /usr/local/bin/ea-php70 /home/xxxxxxxxxx/public_html/app/console mautic:segments:update
5,20,35,50 * * * * /usr/local/bin/ea-php70 /home/xxxxxxxxxx/public_html/app/console mautic:campaigns:update
10,25,40,55 * * * * /usr/local/bin/ea-php70 /home/xxxxxxxxxx/public_html/app/console mautic:campaigns:trigger
*/15 * * * * /usr/local/bin/ea-php70 /home/xxxxxxxxxx/public_html/app/console mautic:social:monitoring
*/15 * * * * /usr/local/bin/ea-php70 /home/xxxxxxxxxx/public_html/app/console mautic:webhooks:process
1,11,21,31,41,51 * * * * /usr/local/bin/ea-php70 /home/xxxxxxxxxx/public_html/app/console mautic:campaigns:rebuild
2,12,22,32,42,52 * * * * /usr/local/bin/ea-php70 /home/xxxxxxxxxx/public_html/app/console mautic:emails:send
23 0,12 * * * /usr/local/bin/ea-php70 /home/xxxxxxxxxx/public_html/app/console cache:clear
27 0 * * * /usr/local/bin/ea-php70 /home/xxxxxxxxxx/public_html/app/console mautic:iplookup:download
*/6 * * * * /usr/local/bin/ea-php70 /home/xxxxxxxxxx/public_html/app/console mautic:messages:send
*/12 * * * * /usr/local/bin/ea-php70 /home/xxxxxxxxxx/public_html/app/console mautic:email:fetch
*/6 * * * * /usr/local/bin/ea-php70 /home/xxxxxxxxxx/public_html/app/console mautic:email:process
*/6 * * * * /usr/local/bin/ea-php70 /home/xxxxxxxxxx/public_html/app/console mautic:queue:process

FYI we cleared this up today, we had to delete the cache folder on the server. Once we did that, it started working. We enabled email notification of cron jobs, and we saw the issue. That fixed it for those of you who need to try something like we did. Why exactly we had to do this, we don’t know.

You are a star, Chris!

This is a 1:45am thank you from New Zealand. Haha!

Paul Stevens from iGo Sales and Marketing had the solution. He is very helpful.