Self-hosted, still stuck
The pitch for a WordPress-native newsletter plugin is ownership. No SaaS landlord, your data on your server. It is a good pitch and mostly true. But ownership without a working exit is a technicality. MailPoet's built-in export handles the simple case fine: one list, standard fields. It gets shaky as your setup grows real: multiple lists with overlapping members, custom fields carrying your segmentation, subscriber statuses you need preserved. The rows come out. The shape of your data does not always come with them.
The custom fields problem, specifically
Custom fields are where a subscriber list stops being a pile of emails and becomes a marketing asset: plan tier, signup source, city, preferences. They are also the first thing awkward exports lose or flatten. Rebuilding them after a lossy export means re-surveying your audience or re-deriving the data from other systems. Both are weeks of work to recover data you technically owned all along.
The direct route
Since the data lives in your WordPress database, the clean fix is to read it there, properly. Our MailPoet exporter works through a tiny read-only connector plugin. Install it, and the tool can pull any list with every custom field, correct statuses and clean encoding, straight to CSV. The connector has no write path in its code at all, so it cannot change or delete anything in your site even if it wanted to. And you can delete it the moment you are done.
Data you cannot fully export is data you are storing for someone else's benefit, even when the server is yours.
When to run it
Before a platform migration, obviously. But also before big WordPress or MailPoet upgrades, before handing the site to a new agency, and on a lazy quarterly schedule as a backup. A complete subscriber export is the kind of file whose value is zero, right up until it is enormous.
Frequently asked questions
How do I export all MailPoet subscribers with custom fields?
The built-in export can struggle with multiple lists and custom field sets. A read-only connector that queries MailPoet's tables directly can export any list with all custom fields, statuses and encoding intact.
Where does MailPoet store subscriber data?
In your WordPress database, in MailPoet's own tables. The data is physically yours, which is why a direct read-only export is possible without involving any external service.
Should I export before upgrading WordPress or MailPoet?
Yes. Major upgrades are the most common moment for data-affecting surprises, and a pre-upgrade subscriber export is a two-minute insurance policy.