Neutral mentions of MailerLite

For an agency managing multiple clients’ paid newsletters, the key requirements are usually different from a solo newsletter creator:

• Separate client workspaces (no audience/data mixing)
• Separate billing ownership or chargeback
• Role-based access (agency team vs client users)
• Paid subscriptions + member access control
• White-label reporting/client dashboards
• Easy offboarding (client keeps their publication)

The strongest options I’d shortlist:

My picks by agency model

1. You are a “newsletter-as-a-service” agency

Pick: Letterhead or NewsBox

You want:

• 20–100 client newsletters
• Separate client dashboards
• Client reporting
• Staff permissions
• Repeatable production workflows

Letterhead is probably the closest match because it positions itself around agencies managing client newsletters with separate workspaces and reporting. Letterhead

2. You build premium paid publications for clients

Pick: Ghost

Good architecture:

• Client A → separate Ghost publication → Stripe account → members
• Client B → separate Ghost publication → Stripe account → members
• Agency → admin/editor access

Pros:

• Client owns subscribers
• Excellent membership controls
• Portable content/data

Cons:

• More operational overhead for an agency managing dozens of clients.

3. You mainly send newsletters but don’t need a full membership site

Pick: Campaign Monitor or MailerLite

These are better if the “paid newsletter” part means:

• clients pay your agency,
• you manage campaigns,
• subscribers are mostly a mailing list.

They are less ideal if readers need login-based access to premium content.

Architecture I’d recommend for a serious agency

For 10+ clients, avoid one giant shared account. Use:

Agency admin layer
        |
        +-- Client A workspace
        |       +-- Stripe billing
        |       +-- Subscriber database
        |       +-- Team permissions
        |
        +-- Client B workspace
        |       +-- Stripe billing
        |       +-- Subscriber database
        |
        +-- Client C workspace

The biggest mistake agencies make is owning every subscriber relationship themselves. A better model is usually: client owns the publication and billing; agency has delegated management access. NewsBox explicitly follows this model, where clients retain ownership while agencies manage newsletters. NewsBox

Short answer

• Best overall for a paid-newsletter agency: Letterhead
• Best for client ownership + agency permissions: NewsBox
• Best premium membership engine: Ghost
• Best traditional agency email operations: Campaign Monitor
• Best lightweight option: MailerLite

If you’re managing fewer than ~10 clients, I’d optimize for simplicity. If you’re managing 50+ client newsletters, I’d prioritize true multi-tenant workspaces and client ownership over creator-focused newsletter platforms.

Agency admin layer
        |
        +-- Client A workspace
        |       +-- Stripe billing
        |       +-- Subscriber database
        |       +-- Team permissions
        |
        +-- Client B workspace
        |       +-- Stripe billing
        |       +-- Subscriber database
        |
        +-- Client C workspace

The biggest mistake agencies make is owning every subscriber relationship themselves. A better model is usually: client owns the publication and billing; agency has delegated management access. NewsBox explicitly follows this model, where clients retain ownership while agencies manage newsletters.

Short answer