This feature requires MailerPress Pro.
SMTP2GO is an email delivery service. Connect it to MailerPress to send your campaigns, automation emails and test emails, and to track bounces (emails returned as undeliverable, for example because the address doesn’t exist).
1. Prepare your SMTP2GO account
- Create an account on the SMTP2GO website or sign in.
- Go to Sending > Verified Senders and add your sender domain. At your domain provider, add the DNS records SMTP2GO gives you (settings that prove you own the domain), then verify the domain.
- Open the API Keys page, create a key for MailerPress and copy it. MailerPress uses this secret key to send through your SMTP2GO account.
2. Link your site with the SMTP2GO API
- Go to MailerPress > Integrations and open the Email Service Providers tab.
- In Other Providers, click Configure on the SMTP2GO card.
- Paste your key in the SMTP2GO API key field.
- Fill in Default sender email address and Default sender name. The address must be a verified sender in SMTP2GO. Empty fields show your global default sender as a placeholder.
- Click Save changes. The card moves to Configured Providers.
- Turn on the card’s Enable toggle, then click Set as primary provider. The card shows the Primary badge: only the primary provider sends your emails.
3. Send a test email
- On the SMTP2GO card, open the Actions menu (three dots) and click Send test email.
- Enter a recipient in Send to and click Send.
You should receive an email with the subject “This is a Sending Method Test”. If the test fails, MailerPress shows the error returned by SMTP2GO:
- 401: the API key is invalid or missing.
- 403: the API key doesn’t have the necessary permissions, or the SMTP2GO account is suspended.
- 422: the sender address isn’t verified in SMTP2GO.
- 429: too many requests. Wait before trying again.
4. Configure the sending speed
- Go to MailerPress > Settings > Sending frequency, or click Adjust sending frequency on the SMTP2GO card.
- Under Configuration Mode, choose Profile and select one of the SMTP2GO profiles below. You can also choose Automatic to let MailerPress pick a profile, or Manual to set your own values.
- Click Save settings.
| Profile | Emails per batch | Interval | Emails per hour |
|---|---|---|---|
| Prudent (Free plan – 1k/month) | 50 | 5 minutes | 600 |
| Balanced (Recommended) | 100 | 2 minutes | 3,000 |
| Performance (Professional plans) | 200 | 2 minutes | 6,000 |
The profiles set the sending pace, not your SMTP2GO quota. Stay within your plan’s monthly allowance.
The sending frequency is saved for the provider that is primary at that moment. Set SMTP2GO as primary before you click Save settings. See How to change your sending frequency in MailerPress.
5. Enable bounce tracking
MailerPress learns about bounces through a webhook: a URL that SMTP2GO calls automatically when an email bounces.
- On the SMTP2GO card, click Configure.
- Turn on Enable bounce tracking. The setting is saved immediately.
- Under Webhook URL, click Copy. The URL looks like
https://example.com/wp-json/mailerpress/v1/esp/bounce/smtp2go. - In SMTP2GO, open the webhooks settings and add a webhook.
- Paste the URL, select the bounce, spam and reject events, and save the webhook.
- If SMTP2GO gives you a signing secret for the webhook (a shared password that proves notifications really come from SMTP2GO), paste it in Webhook signing secret and click Save secret.
Once a secret is saved, MailerPress rejects any SMTP2GO notification without a valid signature. Without a secret, MailerPress only records a bounce if it sent an email to that address through SMTP2GO in the last 30 days.
MailerPress marks the contact as bounced for bounce, spam, reject and failed notifications.
6. Track your bounces
Go to MailerPress > Audience and click the Bounced tab of the contact list. Campaigns only go to subscribed contacts, so bounced contacts no longer receive them.
To compare SMTP2GO with the other sending services, see Choose and configure your email sending service.