Problem with inodes and sending campaign

Mautic version: 3.3.1
PHP version: 7.4.15
Steps to reproduce the error:

i am new on mautic and have less programming knowledge.

I am using SMTP service from share hosting.
i have no problem sending email before, but after problem with inodes on my hosting server, i remove all file *.message on folder …/mautic/var/spool .

After that, i make new campaign with email, but no email received by my recipient.

My question:

  1. Is it safe to remove file *.message in folder …/mautic/var/spool ? If not, what is solution to remove large inodes from mautic?
  2. How to solve problem with my campaign that no email received by my recipient?
  3. Below are the logs file, but i have no knowledge how to solve the problem. Please help me for the solution.

[2021-03-22 06:30:15] mautic.NOTICE: Symfony\Component\Debug\Exception\FatalThrowableError: Call to a member function getHeaders() on bool (uncaught exception) at /mautic/app/bundles/EmailBundle/Command/ProcessEmailQueueCommand.php line 99 while running console command mautic:emails:send
[2021-03-22 06:30:15] mautic.WARNING: Command mautic:emails:send exited with status code 1
[2021-03-22 06:35:12] mautic.NOTICE: Symfony\Component\Debug\Exception\FatalThrowableError: Call to a member function getHeaders() on bool (uncaught exception) at /
/mautic/app/bundles/EmailBundle/Command/ProcessEmailQueueCommand.php line 99 while running console command mautic:emails:send
[2021-03-22 06:35:12] mautic.WARNING: Command mautic:emails:send exited with status code 1
[2021-03-22 06:40:13] mautic.NOTICE: Symfony\Component\Debug\Exception\FatalThrowableError: Call to a member function getHeaders() on bool (uncaught exception) at / /mautic/app/bundles/EmailBundle/Command/ProcessEmailQueueCommand.php line 99 while running console command mautic:emails:send
[2021-03-22 06:40:13] mautic.WARNING: Command mautic:emails:send exited with status code 1
[2021-03-22 06:45:11] mautic.NOTICE: Symfony\Component\Debug\Exception\FatalThrowableError: Call to a member function getHeaders() on bool (uncaught exception) at /
/mautic/app/bundles/EmailBundle/Command/ProcessEmailQueueCommand.php line 99 while running console command mautic:emails:send
[2021-03-22 06:45:11] mautic.WARNING: Command mautic:emails:send exited with status code 1
[2021-03-22 06:50:11] mautic.NOTICE: Symfony\Component\Debug\Exception\FatalThrowableError: Call to a member function getHeaders() on bool (uncaught exception) at / /mautic/app/bundles/EmailBundle/Command/ProcessEmailQueueCommand.php line 99 while running console command mautic:emails:send
[2021-03-22 06:50:11] mautic.WARNING: Command mautic:emails:send exited with status code 1
[2021-03-22 06:55:13] mautic.NOTICE: Symfony\Component\Debug\Exception\FatalThrowableError: Call to a member function getHeaders() on bool (uncaught exception) at /
/mautic/app/bundles/EmailBundle/Command/ProcessEmailQueueCommand.php line 99 while running console command mautic:emails:send
[2021-03-22 06:55:13] mautic.WARNING: Command mautic:emails:send exited with status code 1
[2021-03-22 07:00:16] mautic.NOTICE: Symfony\Component\Debug\Exception\FatalThrowableError: Call to a member function getHeaders() on bool (uncaught exception) at / /mautic/app/bundles/EmailBundle/Command/ProcessEmailQueueCommand.php line 99 while running console command mautic:emails:send
[2021-03-22 07:00:16] mautic.WARNING: Command mautic:emails:send exited with status code 1
[2021-03-22 07:05:10] mautic.NOTICE: Symfony\Component\Debug\Exception\FatalThrowableError: Call to a member function getHeaders() on bool (uncaught exception) at /
/mautic/app/bundles/EmailBundle/Command/ProcessEmailQueueCommand.php line 99 while running console command mautic:emails:send
[2021-03-22 07:05:10] mautic.WARNING: Command mautic:emails:send exited with status code 1
[2021-03-22 07:10:14] mautic.NOTICE: Symfony\Component\Debug\Exception\FatalThrowableError: Call to a member function getHeaders() on bool (uncaught exception) at / /mautic/app/bundles/EmailBundle/Command/ProcessEmailQueueCommand.php line 99 while running console command mautic:emails:send
[2021-03-22 07:10:14] mautic.WARNING: Command mautic:emails:send exited with status code 1
[2021-03-22 07:15:22] mautic.NOTICE: Symfony\Component\Debug\Exception\FatalThrowableError: Call to a member function getHeaders() on bool (uncaught exception) at /
/mautic/app/bundles/EmailBundle/Command/ProcessEmailQueueCommand.php line 99 while running console command mautic:emails:send
[2021-03-22 07:15:22] mautic.WARNING: Command mautic:emails:send exited with status code 1
[2021-03-22 07:20:13] mautic.NOTICE: Symfony\Component\Debug\Exception\FatalThrowableError: Call to a member function getHeaders() on bool (uncaught exception) at / /mautic/app/bundles/EmailBundle/Command/ProcessEmailQueueCommand.php line 99 while running console command mautic:emails:send
[2021-03-22 07:20:13] mautic.WARNING: Command mautic:emails:send exited with status code 1
[2021-03-22 07:25:10] mautic.NOTICE: Symfony\Component\Debug\Exception\FatalThrowableError: Call to a member function getHeaders() on bool (uncaught exception) at /
/mautic/app/bundles/EmailBundle/Command/ProcessEmailQueueCommand.php line 99 while running console command mautic:emails:send
[2021-03-22 07:25:10] mautic.WARNING: Command mautic:emails:send exited with status code 1
[2021-03-22 07:30:14] mautic.NOTICE: Symfony\Component\Debug\Exception\FatalThrowableError: Call to a member function getHeaders() on bool (uncaught exception) at / /mautic/app/bundles/EmailBundle/Command/ProcessEmailQueueCommand.php line 99 while running console command mautic:emails:send
[2021-03-22 07:30:14] mautic.WARNING: Command mautic:emails:send exited with status code 1
[2021-03-22 07:35:21] mautic.NOTICE: Symfony\Component\Debug\Exception\FatalThrowableError: Call to a member function getHeaders() on bool (uncaught exception) at /
/mautic/app/bundles/EmailBundle/Command/ProcessEmailQueueCommand.php line 99 while running console command mautic:emails:send
[2021-03-22 07:35:21] mautic.WARNING: Command mautic:emails:send exited with status code 1
[2021-03-22 07:40:11] mautic.NOTICE: Symfony\Component\Debug\Exception\FatalThrowableError: Call to a member function getHeaders() on bool (uncaught exception) at / /mautic/app/bundles/EmailBundle/Command/ProcessEmailQueueCommand.php line 99 while running console command mautic:emails:send
[2021-03-22 07:40:11] mautic.WARNING: Command mautic:emails:send exited with status code 1
[2021-03-22 07:45:17] mautic.NOTICE: Symfony\Component\Debug\Exception\FatalThrowableError: Call to a member function getHeaders() on bool (uncaught exception) at /
/mautic/app/bundles/EmailBundle/Command/ProcessEmailQueueCommand.php line 99 while running console command mautic:emails:send
[2021-03-22 07:45:17] mautic.WARNING: Command mautic:emails:send exited with status code 1
[2021-03-22 07:50:12] mautic.NOTICE: Symfony\Component\Debug\Exception\FatalThrowableError: Call to a member function getHeaders() on bool (uncaught exception) at / /mautic/app/bundles/EmailBundle/Command/ProcessEmailQueueCommand.php line 99 while running console command mautic:emails:send
[2021-03-22 07:50:12] mautic.WARNING: Command mautic:emails:send exited with status code 1
[2021-03-22 07:55:12] mautic.NOTICE: Symfony\Component\Debug\Exception\FatalThrowableError: Call to a member function getHeaders() on bool (uncaught exception) at /
/mautic/app/bundles/EmailBundle/Command/ProcessEmailQueueCommand.php line 99 while running console command mautic:emails:send
[2021-03-22 07:55:12] mautic.WARNING: Command mautic:emails:send exited with status code 1
[2021-03-22 08:00:18] mautic.NOTICE: Symfony\Component\Debug\Exception\FatalThrowableError: Call to a member function getHeaders() on bool (uncaught exception) at / /mautic/app/bundles/EmailBundle/Command/ProcessEmailQueueCommand.php line 99 while running console command mautic:emails:send
[2021-03-22 08:00:18] mautic.WARNING: Command mautic:emails:send exited with status code 1
[2021-03-22 08:05:11] mautic.NOTICE: Symfony\Component\Debug\Exception\FatalThrowableError: Call to a member function getHeaders() on bool (uncaught exception) at /
/mautic/app/bundles/EmailBundle/Command/ProcessEmailQueueCommand.php line 99 while running console command mautic:emails:send
[2021-03-22 08:05:11] mautic.WARNING: Command mautic:emails:send exited with status code 1