SMTP Error: Could not connect to SMTP host.

Whenever you get a connection error when sending via SMTP like SMTP connect() failed. The most common reason for this problem is that your ESP (Email service provider) you have defined in your delivery settings doesn’t accept one of the used email addresses. Change the from, the reply-to and the bounce address to the email […]

Read More

How can I open the browsers console?

The Browser Console contains important information on Errors. While most of the errors shown are JavaScript related some server related information can get displayed as well. Chrome: Press either CTRL + SHIFT + J to open the “console” tab of the Developer Tools. Alternative method: Press either CTRL + SHIFT + I or F12 to open […]

Read More

SMTP Error: data not accepted

This error occurs if you’re sending via SMTP. The SMTP server rejects the mail for several reasons: Your server dosen’t allow different sender and usernames Some servers require that the From email address is the same as the email address used to authenticate. Check your from name and match it to the username you use […]

Read More

Why my campaigns do not get sent?

If you have created your campaign and it’s ready to get sent you probably see no progress and no mail get sent. Can you send Mails at all? This is essential to send campaigns. Go to Settings => Newsletter => Delivery and test your settings Is your Cron working correctly? Go to Settings => Newsletter => Cron […]

Read More

Why does the unsubscribe link not work?

In some rare cases the generated unsubscribe link in your campaigns ends in a “404 – Not Found” page. Same can happen for the confirm, profile link and sometimes for every link which uses the tracking feature. Make sure Mailster is installed and activated Permalinks work correctly You have setup a newsletter homepage Your server can […]

Read More

Why is my plugin not updating?

In some cases you are not able to update the plugin and you get following error message “Update Failed: Plugin update failed“. There are several reasons this can happen: You haven’t registered yet To get automatic updates and support you need an account at Mailster.co. Click here to register. You haven’t entered a valid License code Make […]

Read More

How can I prevent that my campaigns went in spam folder?

The best way to prevent spam is to run a spam score test. don’t send with you shared host server, use a dedicate ESP instead. Choose your delivery method. use DKIM and SPF for your mails. force users to add you email address to the address book or a whitelist. Check your subject line/text and […]

Read More

Why do the links in my emails not work?

In some cases you were not able to reach the content of one of your links in a Mailster email. The confirmation link isn’t working If your subscribers cannot confirm their subscription please check your permalink structure is working (Settings => Permalink => Save) you’ve setup the newsletter homepage correctly your server can handle redirects […]

Read More

Troubleshooting WordPress in 60 Seconds

Mailster has been tested throughly and follows the WordPress Coding Standards. This means it should work with every plugin or theme which also follows those standards. If you experience any issue it’s often caused by a third party plugin or your current theme.

Read More

Why I get a “Could not execute: /usr/sbin/sendmail” error message?

Sendmail is a mail transfer client which is used on many providers Make sure the the path “/usr/sbin/sendmail” is correct Make sure you have the permission to send with sendmail (ask provider for help). Shared hosts often disabled this function. Try a different sending method at Settings => Newsletter => Delivery Sendmail isn’t designed for […]

Read More

Access to admin-ajax.php is blocked

The admin-ajax.php file is used by Mailster to perform various actions in your backend. If this file is blocked or not accessible it’s most likely Mailster isn’t working correctly.

Read More

SMTP Error: Could not authenticate

In some cases your campaign pauses or you even not able to send mails at all caused by this error: SMTP Error: Could not authenticate. Your credentials are incorrect – double check them! One of your used email addresses are not permitted to use => Use the one you use to authenticate. You probably have […]

Read More

How can I increase my memory limit?

If you get a PHP error like “Allowed memory size of xxx bytes exhausted” you have to increase your memory limit. To do so you have to open the wp-config.php in your WordPress root directory and add following line define(‘WP_MEMORY_LIMIT’, ‘256M’); Some hosts doesn’t allow this changes (or it has no effect). Often it gets […]

Read More

Why is my WordPress version no longer supported?

WordPress gets constantly updated and every update brings new features and fixes bugs. Will the plugin no longer work with a WordPress version which is no longer supported? No, if the plugin worked in the past it will most likely work in the future. Sometimes features not available in this version will cause an error which […]

Read More

How can I send newsletters via GoDaddy?

Although it’s not recommended to use GoDaddy’s own email servers you can do it but have to follow some rules: GoDaddy has a limit of 250 mails from a certain account so make sure you setup the sending limits correctly. Use this form to calculate your values. You have to make sure the used from […]

Read More

Mails are send but not delivered

When Mailster sends an email via your chosen delivery method it always relies on the response of your sending server. Sometimes the message has been sent but not actually delivered.

Read More

My provider doesn’t allow sending bulk mails

Your provider doesn’t allow you to send bulk mails or even block outgoing mails completely. You can always use a dedicate email provider: SendGrid Mandrill Amazon SES Please check out the free plugins for available delivery methods on the WordPress repo

Read More

Why can’t I use SMTP?

SMTP (Simple Mail Transfer Protocol) uses different ports to send mails. Sometime your provider block specific ports and you’re not able to send via SMTP. Some providers also allow only sending only via their own SMTP server and block others completely. The most common ports are 25, 993, 465, 587 for outgoing SMTP connection. To […]

Read More

Why I’m not able to connect to bounce server?

If you setup a bounce server you have to enter a port. Normally 110 or 995 for SSL connections If your get an “Unable to connect to bounce server! Please check your settings” message during testing the connection your host may block connections to the given port. Please check Settings => Newsletter => System Info […]

Read More

Why does tracking not work?

When you send out your campaigns but your statistics say none of your subscriber open or click your campaign follow these steps Send a test campaign By sending a test campaign you can test the links. Mailster will wrap links in tracking links which do not actually track so it wont affect your statistics. If you have […]

Read More

Mailster is not able to access the file system

On some server configurations Mailster isn’t able to write on the file system. You have to change the file permission for WordPress or force WordPress to use the direct method by adding this line in your wp-config.php: define(‘FS_METHOD’, ‘direct’); The error message can be closed (dismissed) after you have added this line. It won’t show […]

Read More

How to solve database errors?

In some cases Mailster is not able to create certain tables in you database. You may end up finding an error similar to Visit the update page to force Mailster to create missing database tables by visiting http://example.com/wp-admin/admin.php?page=mailster_update Please replace example.com with your actual domain. This will run the update progress and problem should be fixed. You […]

Read More

The latest cronjob hasn’t been finished

Sometimes sending emails can take longer than expected. This can cause a server timeout and wrong statistics in some cases. You’ll get a notification in this case: Also if you’re on the cron.php page you get this  If this is a temporary problem and the notification box vanishes by itself you can ignore it but […]

Read More

Why do I get this parse error?

In some rare cases Mailster shows this error after an ajax request doesn’t respond a valid JSON: parsererror 200: SyntaxError: JSON.parse: unexpected character This error is often caused by third party plugins or some unexpected server outputs. Please open the developer console to see the problem of this error.

Read More

Why I can’t save templates or other files

It looks like your WordPress installation isn’t able to write file. You have to change the file permission to the upload folder located in wp-content/uploads and to all it’s sub folders. Read more about file permissions on the WordPress site: Changing File Permissions. You can also force WordPress to write files with FS_DIRECT.

Read More

Mailster doesn’t work with [third party plugin]

We do our best to keep Mailster work best with most common plugin by following the WordPress Coding Standards but sometimes Mailster or a third party plugin breaks caused by the other. Best is to disable one of the plugins and check if the other is still not working. If so the plugin you’ve disabled isn’t […]

Read More