WP Mailster allows your users to be part of a group and communicate by email without having to log into a website.
True two-way group communication over email
WP Mailster allows your users to be part of a group and communicate by email without having to log into a website.
Similar to programs like Mailman or Listserv this plugin allows you to run a discussion mailing list.
That means that every email sent to a central email address is forwarded to the rest of the members of the list.
When members reply to such list emails WP Mailster again forwards them to the other list recipients.
Unlike newsletter plugins this allows true two-way communication via email.
Note: This version of WP Mailster is FREE and limited in terms of number of lists and subscribers per list. Additional features such as captcha protection, double opt-in, email filtering, configurable event notifications, and many others are available in the premium editions.
Please check the documentation on our site as well as look through the FAQs before contacting us. Thank you!
This plugin has been tested on various browsers thanks to BrowserStack!
The dashboard provides an overview of the overall status (mailing list, #emails etc.)
All emails (that are forwarded to the subscribers) are also stored in an email archive in the admin section
Mailing list settings, general settings
Mailing list settings, mailbox (incoming email)
Mailing list settings, mailbox: choose from some pre-configured servers or use your own (what most users do)
Mailing list settings, sender settings (outgoing email)
Mailing list settings, mail content
Mailing list settings, list behaviour
Manage your recipients (per list and/or via custom groups)
Add members to your list (both WP users and users outside WP are possible)
When you want to use WP Mailster you don’t need to browse to a website, login and do something to send the message there – you just use your favorite mail client.
Simply write an email to the mailing list’s address – and nothing else. So use Gmail, Outlook, Thunderbird, a Webmailer, any way you like – just send it to the mailing list address you have setup in WP Mailster.
WP Mailster is a part of WordPress which is a PHP based web application. That means: it can not act/run without being triggered and it can not run forever when triggered. This is a technical limitation coming from PHP, not from WP Mailster or WordPress.
Triggering means that somebody accesses the site. During the page load WP Mailster is handling the jobs to do (mail retrieving/sending). Thus mails can only be send/retrieved when somebody is browsing your site, otherwise the delivery is delayed or never done. As your site might not be browsed every few minutes 24×7 we recommend you to use a cronjob that opens the site periodically. We have a guide on our website on how to set that up.
The send errors are messages your email server is giving back to WP Mailster basically saying “I will not forward this message”. Then WP Mailster sending for some time but eventually stops which is what you see happening.
The cause can be a lot of things, e.g. hitting send limits (per hour/day) or sending email with content that the server does not like.
You need to find out what your email servers are telling WP Mailster. Please follow our troubleshooting guide on our site.
You might get an error message like this when checking the connection settings: “Certificate failure for [server] Server name does not match certificate” or “Certificate failure for [server] unable to get local issuer certificate”.
This is often the case when you use your own mailing server (with a self-signed certificate). To get a connection established, you need to deactivate the automated certificate check. Do this by adding the following line in the special parameter box: /novalidate-cert
Your server needs the PHP IMAP extension installed, otherwise WP Mailster can not work at all. There is nothing that we can do about that, you need to contact your webhoster and see whether they can enable/install the PHP IMAP extension.
If that is not possible you need to use a different webhoster providing a more suitable environment.
Please note that it does not matter whether you want to use IMAP or POP3 for accessing the mailing list inbox. You need the extension in both cases, it is not specific to the IMAP protocol.
In most situations this connection errors show up when your webhoster (where WordPress/WP Mailster is installed) is blocking outgoing connections such as connection attempts to 3rd party email servers. This is done to avoid spam sending.
Please contact your webhoster, so they configure their firewall to allow you to send emails.
Your issue is very likely coming from a large email causing an PHP out of memory error. This is resulting from the fact that every PHP environment has a memory limit. This limit is hit when the email is tried to be retrieved from the mail server.
Please remove this email from the mailing list in question. Either through a mail webfrontend or with the “Delete first email in inbox” tool the “Tools” section in the mailing list’s settings.
In order to prevent have this happen in the future:
A mailing list is a set of recipients that should all get the messages send to the mailing list’s email address.
A group is a way of organizing users. Think of it like a bucket of users. It comes in handy if you want certain users be recipients of multiple mailing lists. Then you would not add the users directly to the recipients of a mailing list, but rather add a group.
An example would be that you have three groups: Management, Project Coordinators and Developers.
If you want to run a company-wide mailing list (e.g. [email protected]) and a project mailing list (e.g. [email protected]) then you would add
Why all that?
In case someone joins the project team you would only add the user to the Developers group. Then the user would be automatically be a recipient of both the project and the company-wide mailing list.
The same thing applies if someone leaves: the user only needs to be removed form the groups and thus is automatically removed from the mailing lists that have this groups as the recipients.
So to sum up: if you run many lists and have many users that are largely managed by the admin, then it might be handy to organize users in groups and add the groups as the recipients.
Release Date – May 24th, 2024
* [Improvement] Automatically shorten (too) long subjects, current max length: 191 characters
* [Bug Fix] Fix email character display/modification issues with Baltic encoding
* [Bug Fix] Fix backend email archive view (and other admin list views) for Safari
* [Bug Fix] Fix some rare cases where email was not saved to database
* [Bug Fix] Fix multiple PHP warnings
Release Date – February 1st, 2024
* [Bug Fix] Fix reCaptcha (v2 is still used)
* [Bug Fix] Fix multiple PHP warnings
* [Bug Fix] Fix multiple PHP deprecation messages (Deprecated: Creation of dynamic property)
Release Date – December 21st, 2023
* [Improvement] CSV import also supports file with only emails (no name column)
* [Improvement] Do not create Microsoft and Google default connections because of missing OAUTH2 support
* [Bug Fix] Avoid error “Prohibited input U+00000081” and update idna-convert library
* [Bug Fix] Fix issue where special characters in subject break user interface (list of archived emails, list of queued emails)
* [Bug Fix] Bounce emails containing email addresses in angle brackets are showing the addresses in the email archive email details view
Release Date – September 4th, 2023
Release Date – August 18th, 2023
Release Date – June 6th, 2023
Release Date – March 29th, 2023
Release Date – February 8th, 2023
Release Date – February 2nd, 2023