Title: Redis Object Cache
Last modified: December 14, 2022

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# Redis Object Cache

 *  Resolved [vorticy](https://wordpress.org/support/users/vorticy/)
 * (@vorticy)
 * [3 years, 5 months ago](https://wordpress.org/support/topic/redis-object-cache-4/)
 * It seems that as Redis Object Cache grows, it will affect the transmission of
   STMP emails.
 * There are two things we see.
 * 1) When doing a test email we get a timeout error on the reply confirmation but
   the email still sends. something like: Domain Check cURL error 28 Resolving timed
   out
 * 2) when sending confirmations to our gmail it is blocked.
 *     ```
       <***@gmail.com>: host gmail-smtp-in.l.google.com[142.251.6.27] said:
           550-5.7.26 Unauthenticated email from ****.com is not accepted due
           to 550-5.7.26 domain's DMARC policy. Please contact the administrator of
           550-5.7.26 ultracornhole.com domain if this was a legitimate mail. Please
           visit 550-5.7.26  https://support.google.com/mail/answer/2451690 to learn
           about the 550 5.7.26 DMARC initiative.
           c8-2002**0jam.69 - gsmtp (in reply to end
           of DATA command)
       ```
   
 * The way I temporarily fix this is by flushing the cache in Redis plugin. But 
   I think after 12hrs it will come back.

Viewing 3 replies - 1 through 3 (of 3 total)

 *  Thread Starter [vorticy](https://wordpress.org/support/users/vorticy/)
 * (@vorticy)
 * [3 years, 5 months ago](https://wordpress.org/support/topic/redis-object-cache-4/#post-16290745)
 * After some more testing, I’m not sure it has anything to do with Redis.
 * It tries to GET from the following but times out:
    [https://connect.wpmailsmtp.com/domain-check/](https://connect.wpmailsmtp.com/domain-check/)?
   mailer=smtp &email=c3VwcG9ydEB1bHRyYWNvcm5ob2xlLmNvbQ= &domain
 * Method URL
    Status
 * All
    Caller Component
 * All
    Size Timeout Time GET [https://connect.wpmailsmtp.com/domain-check/](https://connect.wpmailsmtp.com/domain-check/)?
   mailer=smtp &email=c3VwcG9ydEB1bHRyYWNvcm5ob2xlLmNvbQ= &domain cURL error 28:
   Resolving timed out after 5000 milliseconds WPMailSMTP\Admin\DomainChecker->__construct()
   wp-content/plugins/wp-mail-smtp/src/Admin/DomainChecker.php:56 WPMailSMTP\A\P\
   TestTab->process_post() wp-content/plugins/wp-mail-smtp/src/Admin/Pages/TestTab.
   php:338 WPMailSMTP\Admin\ParentPageAbstract->process_actions() wp-content/plugins/
   wp-mail-smtp/src/Admin/ParentPageAbstract.php:265 do_action(‘admin_init’) wp-
   includes/plugin.php:517 Plugin: wp-mail-smtp 5 5.0291
 *  Thread Starter [vorticy](https://wordpress.org/support/users/vorticy/)
 * (@vorticy)
 * [3 years, 5 months ago](https://wordpress.org/support/topic/redis-object-cache-4/#post-16290748)
 * But if I try it again, it usually works.
 * ‘Method URL
    Status
 * All
    Caller Component
 * All
    Size Timeout Time GET [https://connect.wpmailsmtp.com/domain-check/](https://connect.wpmailsmtp.com/domain-check/)?
   mailer=smtp &email=c3VwcG9ydEB1bHRyYWNvcm5ob2xlLmNvbQ= &domain 200 OK WPMailSMTP\
   Admin\DomainChecker->__construct() wp-content/plugins/wp-mail-smtp/src/Admin/
   DomainChecker.php:56 WPMailSMTP\A\P\TestTab->process_post() wp-content/plugins/
   wp-mail-smtp/src/Admin/Pages/TestTab.php:338 WPMailSMTP\Admin\ParentPageAbstract-
   >process_actions() wp-content/plugins/wp-mail-smtp/src/Admin/ParentPageAbstract.
   php:265 do_action(‘admin_init’) wp-includes/plugin.php:517 Plugin: wp-mail-smtp
   0.2 kB 5 1.2474`
 *  Thread Starter [vorticy](https://wordpress.org/support/users/vorticy/)
 * (@vorticy)
 * [3 years, 5 months ago](https://wordpress.org/support/topic/redis-object-cache-4/#post-16294294)
 * I think I fixed my issue. It was a DNS configuration problem. My server is using
   Ubuntu 22.04.1 LTS and the DNS config file is edited here
 * /etc/resolvconf/resolv.conf.d/head
 * The thing that fixed the slow dns problem was **search** line with the domain
   name. Now when I click the plugins tab for example, it loads in 1sec as opposed
   to 70sec. Before it would have several API calls, but now it says no API calls.
   Not sure what is happening but it is working better.
 *     ```wp-block-code
       # Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
       #     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
       # 127.0.0.53 is the systemd-resolved stub resolver.
       # run "systemd-resolve --status" to see details about the actual nameservers.
       search your-domain.com
       nameserver 8.8.4.4
       nameserver 8.8.8.8
   
       then reset the resolv.conf file and restart bind9
       # resolvconf -u
       # service bind9 restart
       ```
   

Viewing 3 replies - 1 through 3 (of 3 total)

The topic ‘Redis Object Cache’ is closed to new replies.

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 * 3 replies
 * 1 participant
 * Last reply from: [vorticy](https://wordpress.org/support/users/vorticy/)
 * Last activity: [3 years, 5 months ago](https://wordpress.org/support/topic/redis-object-cache-4/#post-16294294)
 * Status: resolved