# Custom SMTP Email Marketing

> Use Custom SMTP with Mailrith to connect an email delivery service for newsletters, campaigns, sequences, automations, and reports.

- Human page: https://mailrith.com/features/custom-smtp-email-marketing
- Markdown page: https://mailrith.com/features/custom-smtp-email-marketing.md
- Page family: Features
- Category: Delivery Control
- Primary keyword: custom SMTP email marketing
- Related keywords: email marketing with an email delivery service, connect an email delivery service, SMTP newsletter platform, use my SMTP for newsletters
- Last reviewed: 2026-07-13

## Direct Answer
Use the email delivery service you already trust, and use Mailrith to manage campaigns, subscribers, forms, automations, and reports.

- Connect Amazon SES, Postmark, SendGrid, Mailgun, Resend, Brevo, or Custom SMTP.
- Keep email delivery costs separate from your Mailrith plan.
- Change email delivery services later without rebuilding your subscriber workflow.

## Most Email Tools Hide The Sender From You
Combined platforms can be easy to start with, but they can hide which service sends your email and how delivery costs are included in the plan.

- **Costs Are Hard To Read:** Contact tiers and send limits can make future list growth costs hard to predict.
- **Service Choice Is Limited:** If you already prefer an email delivery service, many marketing tools still require you to use their sending setup.
- **Delivery Problems Are Harder To Understand:** When a platform hides delivery, it is harder to review delivery events, sending limits, domain setup, and sender settings.

## Why Mailrith Works Well With Your Delivery Service
Mailrith keeps your marketing work in one place while your email delivery service sends each message.

- **Service Choice:** Connect a supported service or choose Custom SMTP, then use that connection for campaigns and sequences.
- **Clear Responsibility:** Mailrith manages subscribers and follow-up. Your email delivery service manages sending, its limits, and its charges.
- **Useful Marketing Tools:** Use subscribers, tags, custom fields, segments, forms, broadcasts, sequences, and automations with your chosen email delivery service.

## What You Can Build With Custom SMTP
This setup works well when you need an email marketing app and want to keep your chosen email delivery service.

1. Add the Custom SMTP connection details and sender details supplied by your email delivery service.
2. Send a test email from Mailrith before you use the connection for campaigns or sequences.
3. Create the form or landing page that collects new subscribers.
4. Build a broadcast, sequence, or automation with that delivery connection.
5. Monitor bounces, complaints, and unsubscribes to help keep the list healthy.

## The Simple Cost Logic
You pay for your Mailrith plan and your email delivery service separately. This keeps the email marketing cost and sending cost clear.

## Estimated SMTP Sending Cost
Custom SMTP does not have one fixed price because the email delivery service is the service you connect. Use this table to estimate sending costs separately from Mailrith.

| Monthly Sends | Delivery Service Cost | How To Read It |
| --- | --- | --- |
| 1,000 emails / month | Service-dependent | Check the pricing for the email delivery service you plan to connect. |
| 10,000 emails / month | Service-dependent | Some services include this sending volume in an entry plan; others charge per 1,000 emails. |
| 50,000 emails / month | Service-dependent | At this volume, compare included emails, overage rates, daily limits, and support options. |
| 100,000 emails / month | Service-dependent | At this volume, also check gradual sending requirements, dedicated IP options, delivery features, and service approval rules. |

Source: [Custom SMTP And Email Delivery Services](https://mailrith.com/guides/smtp-and-delivery-providers). Email-delivery-service estimate only. It excludes Mailrith's subscription and any charges from the service for add-ons, overages, support, dedicated IPs, or higher-volume plans.

## What To Be Honest About
- **You Need A Real Email Delivery Service:** A personal mailbox SMTP account is usually not the right sender for newsletters or campaigns.
- **DNS Still Matters:** SPF, DKIM, DMARC, and sender-domain setup still affect whether inbox providers trust your email.

## Who This Helps
- You already use an email delivery service such as Amazon SES, Postmark, SendGrid, Mailgun, Resend, Brevo, or another service that supplies Custom SMTP settings.
- You want to see sender domains, domain checks, service limits, and delivery costs clearly.
- You need a hosted marketing app instead of a self-hosted email system.

## When Another Tool May Fit Better
- You do not want to manage domain records, Custom SMTP connection details, test sends, or another service account.
- You want email marketing and sending combined under one company and one bill.
- You expect the marketing app by itself to guarantee inbox placement.

## What To Check Before Connecting SMTP
- **SMTP Settings:** Confirm the host, port, username, password or API key, encryption mode, and allowed sender address.
- **Domain Records:** Before you send real campaigns, confirm that SPF, DKIM, and DMARC pass for the sender domain.
- **Service Limits:** Check the service's daily limits, hourly limits, test-account rules, and any required approval step before you plan a send.
- **Event Feedback:** If your email delivery service can send bounce and complaint updates to Mailrith, connect those updates so Mailrith can help protect the list.

## Common Mistakes To Avoid With SMTP
- **Using A Personal Inbox SMTP:** A personal mailbox is usually not built for newsletters or automation. Use an email delivery service designed for this type of sending.
- **Sending From A New Domain Too Fast:** A new sender needs time to build a sending history. Start with small sends to engaged subscribers instead of importing everyone on day one.
- **Forgetting Unsubscribe And Suppression Rules:** Your email delivery service sends each message, but Mailrith still needs to honor unsubscribes and stop sending to bad addresses.

## How Mailrith Fits
Mailrith gives your email delivery service a practical marketing layer: subscribers, fields, tags, segments, forms, landing pages, broadcasts, sequences, automations, and reporting.

- Use a supported service when it is available, or enter the Custom SMTP settings supplied by another email delivery service.
- Send test emails before you use a connection for real campaigns.
- Keep service charges, sending reputation, and limits separate from your Mailrith plan.
- Use the same subscriber tools with any email delivery service you connect through Custom SMTP.

## Decision Table
| Criteria | Mailrith | Other Common Approach |
| --- | --- | --- |
| Setup | You connect the email delivery service through Custom SMTP and test the connection inside Mailrith. | Bundled platforms may need less setup because they manage the sending infrastructure. |
| Control | Your team can view and manage the service choice, sender records, limits, and delivery costs. | Combined platforms may hide service settings and sending details, which can be convenient until you need to understand a delivery problem. |
| Portability | Changing email delivery services means changing the connection, not rebuilding your subscribers, forms, and follow-up. | A fully bundled platform can make the sending layer harder to separate from the app. |
| Best Fit | For teams that want a hosted app with a choice of email delivery service and clear costs. | For teams that want no sender setup and prefer a tool that bundles delivery. |

## How To Send Marketing Email Through Custom SMTP
1. Choose an email delivery service built for newsletters or application email, not a personal mailbox.
2. Set up the sender domain and check service limits before you plan the first send.
3. Create a Mailrith email delivery connection with the Custom SMTP settings supplied by the service.
4. Send a test email. Before launch, fix any domain, connection, or service error.
5. Send first to a smaller engaged segment, then increase volume when bounce, complaint, and unsubscribe activity stays low.

## Plain Facts You Can Rely On
- Mailrith supports Custom SMTP settings and several email delivery services with step-by-step connection guides.
- Mailrith does not sell inbox placement guarantees.
- The email delivery service controls sending, limits, delivery events, and its own charges.
- Mailrith controls the marketing workflow: subscribers, forms, broadcasts, sequences, automations, and reports.
- Good sending still depends on permission, authentication, content, sending pace, and list quality.

## Related Resources
- [Set Up Custom SMTP](https://mailrith.com/docs/setup-custom-smtp): Connect an email delivery service that gives you the required Custom SMTP settings.
- [Email Delivery Connections](https://mailrith.com/docs/email-delivery-connections): Create and test email delivery service connections in Mailrith.
- [Sender Domains And Authentication](https://mailrith.com/guides/sender-domains-and-authentication): Prepare the sender domain before you send to real subscribers.
- [SMTP TLS Checker](https://mailrith.com/free-tools/smtp-tls-checker): Check whether an SMTP server supports secure transport.

## Questions People Usually Ask
### Can I Use Any Email Delivery Service With Custom SMTP?

You can use an email delivery service that gives you the Custom SMTP settings Mailrith needs and allows your type of email. Personal mailbox services often block or limit newsletter sending, so check the service rules before you connect.
### Is Custom SMTP Better Than A Bundled Email Tool?

It depends on your needs. Custom SMTP is useful when you want to choose the email delivery service and see its costs. A combined tool may be better when you want the least setup possible.
### Can I Change Email Delivery Services Later?

Yes. You can create or update delivery connections, then move future emails to the service that fits your needs.