How to Migrate From WP Mail SMTP to Asteris

How do I switch from WP Mail SMTP to Asteris without losing email delivery? Install Asteris alongside WP Mail SMTP (they don’t conflict), configure the same provider in Asteris’s SMTP module, send a test email through Asteris, confirm it arrives, then deactivate WP Mail SMTP. Total time: ~10 minutes. Your Gmail / Microsoft 365 OAuth connection re-establishes during configuration — there’s no automated import, but the steps are short.

Will my Gmail / Microsoft 365 OAuth connection carry over? No, you’ll re-authorise once. OAuth tokens are bound to the originating plugin’s app credentials — Asteris uses its own. Re-authorisation takes ~60 seconds per provider.

Do I lose my email logs when I switch? No — historical WP Mail SMTP logs stay in WP Mail SMTP’s database tables. They’re accessible from WP Mail SMTP’s UI even after you stop using it for new sends. Export logs to CSV before deactivating if you want a permanent record outside the plugin.

Before you start

You need:

Do NOT deactivate WP Mail SMTP before you’ve confirmed Asteris is delivering. The whole point of running them alongside is to keep a known-working fallback while testing.

Step-by-step

1. Install Asteris for WordPress

If you don’t already have Asteris:

Asteris and WP Mail SMTP can both be active simultaneously without conflict.

2. Activate the Asteris SMTP module

In WP Admin → Asteris → Modules, toggle SMTP + Email Logs to ON. The SMTP submenu appears under Asteris.

3. Export your WP Mail SMTP logs (optional)

If you want a record of historical email logs, in WP Admin → WP Mail SMTP → Email Log, click Export to CSV. Save the file somewhere safe. Historical logs stay accessible inside WP Mail SMTP even after deactivating, but the CSV is the format-independent backup.

4. Configure Asteris SMTP with the same provider

In Asteris → SMTP → Settings, select the provider you use with WP Mail SMTP. Asteris supports the same six presets:

Re-enter the credentials. For OAuth providers (Gmail, M365), click Authorise — the OAuth dance happens in a new tab; takes ~60 seconds. For API providers, paste your existing API key. For generic SMTP, the same host/port/username/password you have in WP Mail SMTP works.

Credentials are encrypted at rest with AES-256-CBC.

5. Send a test email through Asteris

In Asteris → SMTP → Test, enter the email address you want to receive at, click Send Test. Wait ~30 seconds.

Check the inbox. If the test arrives, Asteris is delivering. If it doesn’t, check the Asteris → SMTP → Logs tab — the failed send will have a detailed error.

Do not proceed to step 6 until step 5 has succeeded. If you get stuck, [email protected].

6. Disable WP Mail SMTP’s send (but keep it installed)

In WP Mail SMTP → Settings, find the Mailer dropdown and set it to Default (PHP). This stops WP Mail SMTP from intercepting wp_mail() calls without uninstalling the plugin.

Why not deactivate yet? Because both plugins hook wp_mail() — if you simply deactivate WP Mail SMTP first, there’s a brief window where the site falls back to PHP mail. Setting WP Mail SMTP’s mailer to Default first means Asteris becomes the sole wp_mail() handler before any plugin gets deactivated.

7. Verify Asteris is the sole sender

Send another test email through Asteris. Confirm it arrives. Check Asteris → SMTP → Logs to verify the log entry. Send any other test that touches wp_mail() from your site (e.g. trigger a password reset on a test account, submit a form, etc.) — each should land in Asteris’s log.

8. Deactivate WP Mail SMTP

In WP Admin → Plugins, deactivate WP Mail SMTP. Don’t delete it yet — keep it installed but inactive for 30 days as insurance. After 30 days of clean delivery via Asteris, delete it.

Frequently asked questions

Will my Gmail or Microsoft 365 OAuth connection carry over from WP Mail SMTP? No — you’ll re-authorise once during Asteris setup (60 seconds). OAuth tokens are bound to the plugin’s app credentials; each plugin uses its own.

Do I lose my email logs when I switch? No. Historical WP Mail SMTP logs stay in the WP Mail SMTP plugin’s database tables and remain accessible from its UI. Export to CSV before deactivating if you want a portable backup. Asteris starts logging fresh from the moment you activate it.

Can I run both plugins simultaneously? For configuration and testing, yes — that’s the whole approach. For long-term production sending, no — one should handle wp_mail(). The cleanest way to switch is to set WP Mail SMTP’s mailer to “Default (PHP)” before deactivating, so Asteris becomes the sole handler without a fallback gap.

What if Asteris fails to send and I’ve already deactivated WP Mail SMTP? Reactivate WP Mail SMTP. WordPress’s wp_mail() will route through whichever plugin handles it first; if WP Mail SMTP’s mailer is still configured, sending resumes. This is why we recommend keeping WP Mail SMTP installed-but-deactivated for 30 days.

Is there a one-click import for WP Mail SMTP settings? Not in v1.0. WP Mail SMTP’s settings are encrypted with credentials we can’t decrypt without your input. Manual re-entry takes ~60 seconds per provider — acceptable tradeoff for not handling third-party credential decryption.

See the SMTP module → · WP Mail SMTP comparison → · Pricing →