SMTP is the standard protocol used to send email through a mail server. Instead of connecting through a provider API, you connect with a username and password, much like a normal mail app would.
This guide is specifically about agency-side SMTP setup. If you want to let customers connect their own Gmail or Outlook so invites come from their real mailbox, use the dedicated Gmail and Outlook guides instead.
When SMTP makes sense
SMTP works well for smaller-volume agency sending and for cases where the team wants to use an existing mailbox instead of standing up a dedicated API provider.
It is not usually the best choice for larger agency-managed campaign programs because it gives up some of the features agencies often want once campaign volume grows.
- No open or click tracking
- No automatic bounce or complaint handling
- Daily sending limits depend on the mailbox provider
- Best for simpler agency-side sending rather than advanced delivery operations
Agency-side Gmail preset
Gmail is a practical agency-side SMTP option when volume is low and the team wants to start without a separate provider account.
Google requires an App Password for third-party SMTP access when 2-Step Verification is enabled, which means the normal account password is not enough.
- Enable 2-Step Verification on the Google account
- Create an App Password for EmbedMyReviews
- In the SMTP wizard choose Gmail so host, port, and TLS are pre-filled
- Enter the Gmail address and the App Password, then verify the connection
| Account type | Daily limit |
|---|---|
| Personal Gmail | 500 emails per day |
| Google Workspace | 2,000 emails per day |
If verification fails, the most common issue is using the normal Gmail password instead of the App Password.
Agency-side Outlook and Microsoft 365 preset
Outlook follows the same general logic as Gmail, but the daily limits vary much more depending on whether the account is a consumer Outlook mailbox or a Microsoft 365 mailbox.
- Use the Outlook preset in the SMTP wizard so host, port, and TLS are pre-filled
- If 2FA is enabled, use an App Password rather than the normal account password
- Verify the connection before moving on to sender settings
| Account type | Daily limit |
|---|---|
| Outlook.com or Hotmail | 300 emails per day |
| Microsoft 365 | 10,000 emails per day |
Agency-side Custom SMTP setup
Custom SMTP is there for mail servers that are not Gmail or Outlook, such as company mail servers, hosting SMTP, Yahoo, Zoho, or dedicated relays.
This path gives full control over host, port, encryption, username, and password, but it also assumes the operator knows what their mail server expects.
- Use port 587 with TLS in most modern setups
- Use port 465 with SSL when the provider specifically requires it
- Do not include http or https in the host field
- Verify the connection before trusting the configuration
Customer mailbox setup belongs in separate guides
Customer-owned Gmail and Outlook connections are important enough to deserve their own guides because the setup flow, troubleshooting, and credit behavior differ from agency-side SMTP.
If your goal is to let customers send review requests from their own mailbox, go to the dedicated Gmail and Outlook guides next.
- Use `Setting Up Gmail for Customers` for Google accounts
- Use `Setting Up Outlook for Customers` for Outlook or Microsoft 365 accounts
- Customers do not get a Custom SMTP option in their own wizard
Customer-owned Gmail and Outlook sending is the main exception where invite emails do not consume the normal customer plan email credits.
Daily limits and deliverability trade-offs
SMTP is workable, but it is not built for the same operational depth as API-based providers. Daily mailbox limits are lower, reputation signals are less controllable, and there is no built-in tracking or bounce automation here.
That means SMTP is usually best for lighter use cases, while dedicated API providers are better for serious agency-managed campaign volume.
- Use conservative throttling with Gmail and Outlook
- Do not treat a personal mailbox like a bulk email platform
- If delivery quality or scale becomes a recurring issue, move to SendGrid, Brevo, Mailgun, Postmark, SES, or another dedicated provider
How SMTP interacts with custom-plan credits
Agency-managed SMTP sending still follows the normal customer custom-plan invite credit rules. The provider type changes the delivery method, not the plan limit model.
The important exception is customer-owned Gmail or Outlook sending from inside the customer account. In that case, invite emails do not consume the normal customer plan email credits.
- Transactional emails remain separate from invite credits
- Agency-managed SMTP still respects the customer plan email limit
- Customer-owned Gmail or Outlook sending is the main credit exception