Sending Does Not Work

If you have been through the basic steps in setting up the MailPoet plugin, and outgoing emails still appear to not be sending, here are some possible sources of issues and how to find and debug them.

Quick links:

Plan Issues

If you are sending with our MailPoet Sending Service, you will require an account and plan with us (our Free plans include MSS sending service, so a paid plan is not a requirement). If there are any issues with your connected plan, then sending may be paused.

Key Activation Issues

Under MailPoet > Settings, on the "Key Activation" tab, double check your key to make sure it is entered correctly.

Click the "Validate" button to re-validate your key to make sure the connected plan is still active; resetting the connection in this way can sometimes clear plan connection issues. 

If your key activation tab indicates that your brand new plan is not yet approved, this means it is still under review by our team. In this case, please check your email for a message from us requesting further information for the approval to pass. 

If you have reached your plan's limit for either number of subscribers or number of emails sent, you should see a notice in your dashboard and may also have received an email with a warning. Please visit your account on to upgrade to a larger plan.

If your Key Activation tab shows an error connecting to our server, which is, please contact your hosting company to have our server whitelisted.

Poor deliverability rate

If you're sending with MailPoet Sending Service and we've detected too many bounces or spam complaints from your lists, your account will be marked as banned according to our Anti-Spam policy

This means your sending will be temporarily suspended. If you have a paid plan with us, you should receive an email notification about the suspension. Paid and free plans will also see this warning on the  Emails page:

Our goal is to work with you to resolve issues with your site and mailing list to ensure your mail is going only to engaged subscribers who will love your content. Please respond to our email or raise a ticket with us to resolve the issues and reactivate sending on your account.

Read more: What Happens When the MailPoet Sending Service is Paused for My Account?

Mail Quality Issues

If it seems like MailPoet is sending out emails, but no emails at all are being delivered, then there may be an issue with the emails you are sending out. Here are a few things to check:

  • Make sure your "From" email address is not a free email address (Gmail, Yahoo, Hotmail) and is specific to your domain. Remember to update these values on any Post Notification, Automation, or Newsletter templates you may be using.
  • Make sure your "From" email address is not a role-based email.
  • Use the same "From" and "Reply-to" address under MailPoet > Settings on the "Basics" tab. Some mail services will mark emails with different email addresses here as spam. Remember to update these values on any Post Notification, Automation, or Newsletter templates you may be using.
  • Check for blacklisted domains and links, or other content issues with your emails, using Mail Tester - instructions here.

Domain Authentication Issues

To meet new guidelines from big email service providers like Google, Yahoo, Hotmail, and Outlook for 2024, we now require all plans that send through MailPoet Sending Service to have an authenticated domain. 

If you are seeing a notice on your site that your domain is not verified, or that your DMARC policy has been violated, then please follow the steps to authenticate your domain.

Read more: Google, Yahoo, and other Big Email Service Provider Requirements

Task Scheduler, Cron and Sending Queue errors

You can check for task scheduler, cron, and sending queue errors in  MailPoet > Help > System Status tab. You might see errors shown under Cron or under the Sending Queue, or you might see a "Connection unsuccessful" warning under the Task Scheduler.

Note that when reaching out to support for additional information or help with these types of errors, please include a screenshot of your System Status showing the error message with your request.

Task Scheduler Connection Unsuccessful

The task scheduler ensures that your emails are processed and dispatched on time, running as a background process that accesses your website to schedule and process the sending of newsletters. Sending won’t work if the connection can’t be established for any reason.

If sending is stuck at 0% or Post Notifications and Welcome Emails are not sent at all, this could be due to the Newsletter Task Scheduler not being able to start. You will see a "Connection unsuccessful" warning on the System Status page in the Task Scheduler area.

If the connection shows here as unsuccessful, click on the hyperlinked URL below the  Task Scheduler heading.

A new page will open with one of the 2 possible responses:

  1. your website's homepage/static page instead of "pong" (which is the expected response for a successful connection)
  2. an error message

If you are seeing a Task Scheduler issue, please change your settings under MailPoet > Settings on the "Advanced" tab under "Newsletter Task Scheduler" to the "WordPress built-in cron (recommended)" setting. You can also verify under Tools > Scheduled Actions that the "mailpoet/cron/daemon-trigger" action is scheduled and running with no errors.

If you continue to see errors, then the issue is most likely a website host server configuration issue (Cloudflare rules are a common issue here). You can:

  • Switch to using Linux Cron (i.e. server side cron) - instructions here
  • Reach out to your website host to resolve any cron issues or security rule issues on their side - please share with them the error message shown when checking the cron link on the System Status page

Cron or Sending Queue Errors

If you are seeing an error that the Sending Queue is paused and an error message in the Sending Queue box, then you may be able to resolve the issue yourself if it is one of these common MailPoet errors.

1. cURL timeout (cURL issue 28)

This issue means that the timeout limits on your hosting account are too low, and are causing some features to end before they have had a time to complete.

Solution: Upgrading your hosting package is always an option, but as an intermediate step, you can get in touch with your hosting provider's technical support and send them this:

Hi support! cURL requests on my website frequently time out.

This is causing issues with certain WordPress plugins, like MailPoet, which run background processes.

Is it possible to increase the cURL timeout limit?

You can also attempt to change your timeout settings directly. Find out more on how to do this here.

2. cURL forbidden

This issue means that a specific page on your site is being blocked on your website hosting server side, likely by some type of restrictive security rule.

Solution: get in touch with your hosting provider's technical support and send them this:

Hi support! We get a cURL forbidden on this page: PASTE URL OF THE ERROR MESSAGE HERE 

Is it possible to white list this URL?

3. cURL SSL connect error (cURL issue 35)

The cURL error 35 can appear when the cURL function cannot connect to your website using SSL. This is a website hosting server configuration issue.

cURL often uses a different set of certificates, shipped with PHP. There are several things that can cause this problem, in most cases updating both cURL and PHP to a newer version will resolve this issue.

In rare cases, the issue may be related to a block on the server side to our key validation server,

Solution: Please reach out to your web host to ensure that cURL and PHP are both upgraded to the latest version on your account. In addition, ask them to check for any other cURL configuration issues and to whitelist our server if necessary. More on this issue here.

4. The website is behind a proxy

This is unusual, but it can happen with intranet sites that are protected behind a firewall.

Solution: activate Server side cron (Linux cron) in your MailPoet Settings > Advanced > Newsletter task scheduler (cron). See guide.

5. All other common errors

  1. The Task Scheduler URL is returning your homepage.
  2. The hosting provider is blocking HTTP loopback connections (e.g. your site → your site).
  3. Restrict access/security plugins preventing it to work (e.g. iThemes Security Plugin, WordFence, WPMUDEV Privacy Plugin, Ninja Firewall plugins). To completely rule out your site's code as a root cause, please run a full conflict test.
  4. The site is too slow to respond (e.g., operation timed out).

Solution: activate Server side cron (Linux cron) in your MailPoet Settings > Advanced > Newsletter task scheduler (cron). See guide.

Finding a bug

If you are not seeing any of the above errors, you can check for additional error information under MailPoet > Settings on the "Advanced" tab. 

Scroll down under "Logging" and click the "View Logs" link to view any logs. Please note that if the logs here were set to record "Nothing" you will need to change this to either "Everything" or "Errors Only" and then run a new test to generate a meaningful error log.

On the error logs page, use CMD+CLICK to view the full error message.

Please copy any relevant messages in the logs - or, if you are seeing a fatal error, the full stack trace that is showing - and open a ticket with us to investigate. Please also include the text of your "System Info" tab under MailPoet > Help and screenshots of your "System Status" tab as well.

You can contact us here.

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