How to fix 502 Bad Gateway when sending an email?

Question

PHP

Hello. I ran into a problem that when sending a letter I get a 502 error
when I send html, that is, But I don’t get an error when sending raw text, like this Error logs:
Mail::send('view', $data, $callback);
Mail::raw('Some text', $callback);

*20639 recv() failed (104: Connection reset by peer) while reading response header from upstream,
upstream: "fastcgi://unix:/var/run/php-fpm/php-fpm.sock:"

WARNING: [pool site.com] child 16813 exited on signal 11 (SIGSEGV) after 51.029643 seconds from start

Googled the problem a lot, but did not solve it (
If you need any additional logs, write about it.

Answer 1

Falls off on timeout.
Set up your email provider.
If this is not a local provider, then use queues and send emails from background processes.

Answer 2

Adjust the server to use less memory. In your "dmesg | tail" you can clearly see that the server is killing processes because it runs out of memory.
Solutions include:
- decreasing pm.max_children in the PHP-FPM settings
- allocating a larger swap file
- decreasing the size of MySQL buffers. In general,
the most basic setting So you can wait for any problems here before the problem of lack of memory is not solved.