Post SMTP vs Solid Mail
Updated 11 Oct 2026. 23 features compared side by side.
SMTP and API mailer plugin with free email logs, fallback SMTP, failure alerts and a mobile app; Pro adds Microsoft 365, SES and tracking.
Free SMTP plugin from SolidWP (formerly WP SMTP, now moving to Kadence) with provider presets, From-based routing, fallback and an email log.
Choose Post SMTP if…
- You need Gmail & Google workspace and failure alerts
- You also want Microsoft 365 / Outlook and resend from the log
- You want the more complete feature set (90/100 vs 40/100)
- You prefer the more widely used option
Choose Solid Mail if…
- You need smart routing and no paywalled mailers
Post SMTP includes 9 features that Solid Mail lacks, including Gmail & Google Workspace, Microsoft 365 / Outlook and Setup wizard; Solid Mail has 2 that Post SMTP lacks, including Smart routing and No paywalled mailers. Both include 10 of the 23 features we track. 1 feature is not yet verified for one or both plugins.
At a glance
Feature comparison
Click a screenshot to see both plugins side by side.
Post SMTP Solid MailSending & mailers7/85/8
Other SMTP option connects to any SMTP server.
Manual SMTP connection for any host with port, encryption and authentication.
Core plugin includes API sockets for SendGrid, Mailgun, Brevo, Postmark, SparkPost, Mailjet and more.
Presets for SendGrid, Mailgun, Brevo and Postmark; most connect via the provider's SMTP relay, not its API.
Gmail API with your own OAuth client is free; one-click Gmail setup needs Pro.
No Google OAuth; Gmail works only through manual SMTP with an app password.
Office 365 connection needs Pro; Microsoft one-click setup is in Business.
No Microsoft OAuth; Outlook/365 only via manual SMTP settings.
Amazon SES is a Pro mailer, included from the Basic plan.
SES preset uses SES SMTP credentials and endpoint rather than the SES API.
Fallback SMTP takes over when the primary fails; Pro adds more connections.
Default connection plus 'Use Alternative Connections on Failure' retries via other connections.
No rule-based routing; extra connections act only as fallbacks.
Each connection handles emails from its own From address; no other rule types.
Three-step wizard: choose mailer, configure, send test email.
Per-provider setup forms but no guided wizard; test email is a separate tab.
Logs & monitoring7/73/7
Detailed log with status, errors, filters and print option in the free plugin.
Mail Log records sender, recipient, subject, time and SMTP errors.
Resend individual emails from the log; bulk resend needs Professional.
No resend option in the log.
Report and tracking extension tracks opens only, not clicks; plan not specified.
No open or click tracking.
Free alerts by email, Slack, Pushover, Chrome extension or app; Twilio and Teams are Pro.
No email or chat alerts when sending fails.
Auto-retry a set number of times, with batching and quota scheduling.
Failed sends are retried immediately through another connection; no queue or delayed retries.
Free weekly summary of totals and failures; Pro adds health reports and graphs.
No charts or summary reports.
Free caps the number of stored log entries; day-based retention and attachments need Pro.
Logging can be turned off and logs deleted or exported; no automatic retention period.
Email control3/42/4
Settings prevent plugins from changing the From email and From name.
Each connection stores a From name and email, but there is no option to force one sender on all emails.
No option to disable individual WordPress notification emails.
No options to disable individual WordPress or WooCommerce emails.
Run mode can log emails only, or ignore them, instead of delivering.
No option to block or simulate outgoing email.
Send Test Email tool plus an email tester with spam score checks.
Email Test tab sends a test through a chosen connection and records errors.
Security & admin3/42/4
Authentication credentials, including fallback SMTP, can be set as wp-config constants.
Credentials are kept in the database without encryption; wp-config support was legacy (v1.1.10).
Multisite supported with global network settings in the free plugin.
Multisite support is not documented.
Microsoft 365, Amazon SES and Zoho mailers are Pro-only.
Free plugin with no paid edition; all providers included.
Documented action and filter hooks; constants for logging and auth.
REST endpoints for connections and a few filters; no documented hooks or WP-CLI.
Statuses: Yes Pro Add-on Partial 3rd-party No ?
Pricing compared
Post SMTP Freemium
| Free | $0 |
|---|---|
| Free | Free per year, Unlimited |
| Basic | $59.99 per year, 1 site |
| Professional | $79.99 per year, 1 site |
| Business | $99.99 per year, 1 site |
Solid Mail Free
| Free | $0 |
|---|---|
| Free | Free per year, Unlimited |
Downloads trend
Post SMTP
18,588 downloads last week
Solid Mail
1,363 downloads last week
Verdict
Post SMTP scores higher on our feature checklist (90/100 against 40/100) and includes Gmail & Google workspace, failure alerts and Microsoft 365 / Outlook that Solid Mail does not. Solid Mail still has the edge on smart routing and no paywalled mailers. Check the features you rely on in the table below before deciding.
Biggest differences
Post SMTP: included. Solid Mail: not included. Gmail API with your own OAuth client is free; one-click Gmail setup needs Pro.
Post SMTP: included. Solid Mail: not included. Free alerts by email, Slack, Pushover, Chrome extension or app; Twilio and Teams are Pro.
Post SMTP: paid version (Basic). Solid Mail: not included. Office 365 connection needs Pro; Microsoft one-click setup is in Business.
Post SMTP: included. Solid Mail: not included. Resend individual emails from the log; bulk resend needs Professional.
Post SMTP: included. Solid Mail: not included. Authentication credentials, including fallback SMTP, can be set as wp-config constants.
Post SMTP: not included. Solid Mail: partial. Each connection handles emails from its own From address; no other rule types.
Written from the feature, pricing and install data on this page, not from hands-on testing. How we compare.
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FAQ
Which is better, Post SMTP or Solid Mail?
Post SMTP scores higher on our feature checklist (90/100 against 40/100) and includes Gmail & Google workspace, failure alerts and Microsoft 365 / Outlook that Solid Mail does not. Solid Mail still has the edge on smart routing and no paywalled mailers. Check the features you rely on in the table below before deciding.
Which has more features?
Post SMTP includes 20 of the 23 features we track, against 12 for Solid Mail. Feature count is only part of the picture; check which of the differences matter to you.
Is Post SMTP free?
Post SMTP has a free version on WordPress.org. Paid plans start at $59.99/yr.
Is Solid Mail free?
Solid Mail has a free version on WordPress.org.
Feature data last changed 11 Oct 2026. Spotted something wrong? Suggest an edit to Post SMTP or Solid Mail. Some links are affiliate links. We may earn a commission at no cost to you; it never affects our data or rankings.