True two-way group communication over email
Allow 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 emails WP Mailster again forwards them to the other list recipients.
Unlike newsletter plugins this allows true two-way communication via email.
- group communication through email
- usable with any POP3/IMAP email account
- recipients can be managed in the WordPress admin area
- users can subscribe/unsubscribe through widgets on the website
- all WP users can be chosen as recipients, additional recipients can be stored (without having to create them as WP users)
- users can be organized in groups
- single users or whole groups can be added as recipients of a mailing list
- replies to mailing list messages can be forwarded to all recipients (or only the sender)
- email archive for browsing the mails
- full support of HTML emails and attachments
- custom headers and footers
- subject prefixes
- many more features
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.
How do I send an email?
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.
Why take the emails so long to be delivered? How can I speed up sending?
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.
What are send errors?
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.
Contributors & Developers
“WP Mailster” is open source software. The following people have contributed to this plugin.Contributors
Release Date – February 2nd, 2023
- [Bug Fix] Email without TO recipient will not stop email(s) from being retrieved from mailing list inbox
- [Bug Fix] Fix PHP include problem related to library Html2Text (and others)
- [Bug Fix] The add2Group parameter works in the subscribe-shortcode
- [Bug Fix] Ability to deal with charset collation differences (between WP users and WP Mailster database tables)
- [Bug Fix] Avoid PHP warnings in PHP 8.1
Release Date – January 9th, 2023
- [Improvement] Better warn about non-supported special characters in the mailing list password(s)
- [Improvement] UI improvements (show attachment indicator in email archive, explain fwd errors/completed indicators)
- [Improvement] Add list name in List-Subscribe / List-Unsubscribe headers (subject lines)
- [Bug Fix] Fix issue when no iconv functionality is available for charset conversion
- [Bug Fix] Fix PHP errors (PHP 8)
- [Bug Fix] Saving WP user’s lists/groups will not cause incorrect error message
- [Bug Fix] Do not show current date/time in send timestamp column when sending was not done
- [Bug Fix] Fix some language typos
Release Date – October 20th, 2022
- [Improvement] For address mode = TO (single recipient per email), pre-fill email address in unsubscribe links
- [Improvement] Stop using $_SESSION to avoid problems with WP health check etc.
- [Improvement] Introduce various filters for altering the subscribe/unsubscribe endpoints headers, text and buttons
- [Improvement] Introduce filter wpmailster_email_processing_attachment_default_filename to override default attachment filename (mst_no_filename) if needed
- [Bug Fix] Subscribe and unsubscribe dialogs can now be translated
- [Bug Fix] Fixed unsubscribe problem: when for one email address, there is a both a WordPress and a WP Mailster user, both get unsubscribed
- [Bug Fix] License key can be saved in WP Mailster settings if ad-hoc check/validation fails
- [Bug Fix] Change license backend callbacks to be executed server side (to avoid issues with CSP / Content Security Policy blocking in browsers)
- [Bug Fix] Remove several PHP notices
Release Date – August 23rd, 2022
- [Improvement] Store log file now in wp-content/uploads/wp-mailster directory to avoid problems on plugin updates/upgrades/downgrades
- [Bug Fix] mst_emails shortcode’s list ID (lid) filter works again
- [Bug Fix] Goodbye/welcome messages were not sent in some situations where admin changed list memberships
- [Bug Fix] Support special characters in passwords (slash, “/”, was missing)
Release Date – July 27th, 2022
- [Improvement] Update minimal system requirements to WP 5.3 (from 4.3) and PHP 5.6 (from 5.5)
- [Bug Fix] Storing of attachments with long MIME subtypes (e.g. MS Office formats like docx format with: VND.OPENXMLFORMATS-OFFICEDOCUMENT.WORDPROCESSINGML.DOCUMENT) is supported and will not crash mail retrieving
- [Bug Fix] Fix issues managing users with apostrophe in their names (like O’Neil)
- [Bug Fix] Fix issues recording send events for users with apostrophe in their names
- [Bug Fix] Omit PHP warnings like “DOMDocument::loadHTML(): Tag o:p invalid in Entity”
- [Bug Fix] Fix issue with timestamps not taking WP timezone settings into account
- [Bug Fix] A “mail not forwarded” event not being sent out (due to random reasons) will not stop handling of mailing list mails (not cause email loop)
- [Bug Fix] Failure to open the log file will not crash the process
Release Date – June 10th, 2022
- [Feature] Introduce subscribe and unsubscribe shortcodes ([mst_subscribe] and [mst_unsubscribe])
- [Improvement] UI optimization: full width for emails/lists/users/groups/servers/… table views
- [Bug Fix] Fix for moderation mode: bounced/blocked/filtered emails will not produce a moderation request
- [Bug Fix] Fix handling of certain binary attachments
- [Bug Fix] Fix database issues (db maintenance) on WP multisite installations