System requirements¶
Check this list before you install the plugin. What follows is not a recommendation but a precondition: below it, the plugin either will not start or individual features fail silently.
You can find your own values under Tools → Site Health → Info. WordPress version, PHP version, database and the loaded PHP extensions are all listed there together.
The essentials¶
| At least | Tested against | |
|---|---|---|
| WordPress | 5.5 | 7.1 |
| PHP | 8.1 | 8.3 and 8.4 |
| Database | whatever WordPress itself requires: MySQL 5.5 / MariaDB 10.0 | MariaDB 11.4 |
The WordPress and PHP values are also in the plugin header and in
readme.txt. WordPress reads them and will not even let you activate the
plugin on an installation that is too old.
PHP extensions¶
On any usual hosting the first four are present. They are listed so that you know where to look if something goes wrong.
| Extension | What for | Without it |
|---|---|---|
dom |
Backing up settings; embedding images in the mail | Both abort |
simplexml |
Reading settings back in | The backup file cannot be loaded |
mbstring |
Labels and charts of the Statistics | The statistics page aborts |
openssl |
Storing passwords encrypted | Credentials do not make it into the backup file (Settings backup) |
soap |
only for the SOAP interface | The module says so when you switch it on and answers callers with HTTP 503 instead of the white error page |
Sockets (fsockopen) |
only for Bounce processing and for SMTP | The mailbox cannot be fetched |
The last two are occasionally missing on shared hosting, and both affect only one module. The others are only noticeably absent if you use the corresponding feature.
What else is needed¶
A mail route. Without a way out, even the best plugin sends nothing. The
options are the server's own mail (mail()), an SMTP account or an SMTP
plugin. Which route is right when is described under
Sending settings.
A sender address on your own domain, with SPF and — if possible — DKIM set up for it. Without that, your newsletters increasingly end up in spam, and the plugin cannot change it; the recipient's mail server decides.
A cron that runs. Sending happens in portions, triggered by WP-Cron. WP-Cron depends on page views: on a site nobody visits for days, it does not run. In that case set up a real cron job — the path and the address for it are under Sending settings.
Enough memory for PHP. There is no fixed number — it depends on the theme, the plugins and the size of your lists. WordPress recommends 64 MB as a lower bound; when a list in the backend breaks off with a blank page, it is almost always this. The value is under Tools → Site Health → Info.
Write access to the uploads directory. The plugin stores attachments and
your own templates under wp-content/uploads/wpng/. The directory follows the
WordPress upload path and cannot be configured separately.
What is not needed¶
This list matters just as much as the one above — it says what you do not have to order from your host:
- No Node, no Composer, no shell. The plugin runs on shared hosting, without exception. It calls no system commands.
- No external service. No account with a delivery provider, no sign-up anywhere. The subscribers live in your database, and mail goes out over your mail route.
- No connection to our servers. The shipped plugin opens no connection to maennchen1.de at runtime. The one exception is the update check in the paid package, and that only asks for a version number.
- No WP-CLI. Everything an operator has to do is reachable in the backend. The plugin's WP-CLI commands are a development tool.
- No bundled library. What is needed — PHPMailer, jQuery, the editor — WordPress brings along itself.
Multisite¶
The plugin runs in a multisite network. The tables then exist once for the
whole network, not per blog: the table prefix comes from
$wpdb->base_prefix. All blogs therefore share subscribers, groups and
newsletters.
For a network you need the Enterprise edition — the Pro edition covers a single domain. The comparison is under Lite, Pro and Enterprise.
That is a decision, not a limitation — but it has to fit your case. If every blog needs its own subscriber list, a multisite with this plugin is the wrong setup.
Limits on volume¶
There are none. Neither the free nor the paid package limits the number of subscribers, groups, newsletters or sends.
What does exist is the reality of the server: a shared hosting package does not send 50,000 mails in an hour, and many hosts explicitly cap the number of mails per hour. Ask them before you build a large list — and set Newsletters per run accordingly.