Trusted email delivery for WordPress
Send slower. Land in more inboxes.
Flex Slow Mail paces your WordPress campaigns to a rhythm inbox providers trust — protecting your sender reputation while your open rates climb.
14-day trial on Pro Single · 7-day money-back guarantee · Uses your own SMTP
Bulk sending in one burst is how you get blocked
Blasting a list all at once trips spam filters and blows past your provider's rate limits. Flex Slow Mail sends one configurable batch per WP-Cron cycle, spreading a large campaign over hours or days so your domain keeps its reputation intact.
- Batch size per cycle
- Optional delay between sends
- Automatic pause outside your sending windowPro
How it works
Connect your SMTP
Add a profile for Gmail, SendGrid, Mailgun, Amazon SES, Brevo or your own mail server. Test the connection before you save it.
Upload your list
Import a CSV or TSV. Duplicates and suppressed addresses are filtered out automatically at import.
Build the campaign
Write your subject and HTML body, pick one or more lists, then choose Send Now, Schedule Later, or a Time Slot window.
Send at a safe pace
WP-Cron processes one batch a minute. Watch sent, pending and failed counts update live, and pause or resume at any point.
Features
Paced batch sending
One batch per WP-Cron cycle, with a configurable batch size and an optional delay between individual sends.
Your own SMTP server
No per-email fees and no third-party sending limits. Route through any provider you already pay for.
Encrypted credentials
SMTP passwords are encrypted with AES-256-CBC before they ever touch the database.
CSV & TSV list import
Upload subscriber lists with automatic de-duplication and suppression filtering at import time.
Time Slot sendingPro
Restrict sending to chosen days and hours — business hours only, for example. Campaigns pause automatically outside the window.
Full analytics dashboardPro
Per-campaign open rates, click rates and a per-link breakdown. Delivery stats and open tracking are included free.
Suppression & unsubscribe
A global block list plus a token-signed one-click unsubscribe link in every campaign email.
Pause, resume & retry
Stop a campaign at any point and resume exactly where it left off. Bulk-retry failed sends without duplicating deliveries.
Debug log & GDPR controls
A filterable log viewer for queue, cron and SMTP events, with configurable analytics retention periods.
Free vs Pro comparison
Simple, transparent pricing
Every paid plan includes a 7-day money-back guarantee. Pro Single starts with a 14-day free trial — no charge until the trial ends.
Prices in USD. Local taxes calculated at checkout.
Integrations
Already using an SMTP plugin? Pro
On Pro, Flex Slow Mail hands sending to a plugin you have already configured — no second set of credentials to manage.
WP Mail SMTP
FluentSMTP
Post SMTP
Easy WP SMTP
Gmail SMTP
SMTP Mailer
Support
Frequently asked questions
Start sending at a pace that protects your domain
Install the free version today, or go Pro for unlimited campaigns and full analytics.