Connect your own SMTP server
Point Sumezi at your own SMTP provider — every plan sends through your own server.
Before you start
By default, Sumezi sends your campaigns through its own shared mail infrastructure. If you'd rather send through your own mailbox or a transactional email provider — for your own sending reputation, higher volume, or your company's compliance requirements — you can connect it under Settings, SMTP.
SMTP settings and sender details live in two panels under Settings, Sending: SMTP (host, port, credentials) and Sender (from name and from email).
Step 1 — Get your provider's credentials
Before you touch Sumezi, get the SMTP host, port, username and password from whichever mailbox or provider you want to send through — Gmail, Microsoft 365/Outlook, a transactional provider like Postmark, SendGrid or Mailgun, or your own company mail server. Most providers list these under a "SMTP" or "App passwords" section of their account settings.
Using 2-factor authentication? Gmail, Microsoft 365 and most other providers won't accept your normal login password for SMTP once 2FA is on — generate an app-specific password instead and use that as the Password field.
Step 2 — Fill in your SMTP settings
On the SMTP page, fill in the following fields exactly as your provider specifies them:
| Field | What to enter |
|---|---|
| Host | Your provider's SMTP server address — e.g. smtp.gmail.com, smtp.office365.com, smtp.postmarkapp.com, smtp.sendgrid.net, smtp.mailgun.org, or your own mail server's hostname |
| Port | 587, 465, or another port your provider specifies |
| Encryption | STARTTLS, SSL/TLS, or None — must match the port (see below) |
| Username | Your mailbox login or provider account username — usually your full email address |
| Password | Your mailbox password, or an app-specific / API password |
| From name | The name recipients see as the sender |
| From email | The address mail appears to come from — often must match the account you authenticate with |
STARTTLS, SSL/TLS or None?
- STARTTLS (port 587): the most common setup for external providers. Sumezi connects in plain text, then upgrades the connection to encrypted before logging in. Use this unless your provider says otherwise.
- SSL/TLS (port 465): the connection is encrypted from the first byte, no upgrade step. Some providers only offer this mode, or prefer it.
- None: no encryption at all. Only use this if your provider explicitly tells you to — virtually no external provider (Gmail, Microsoft 365, Postmark, SendGrid, Mailgun, or a typical company mail server) recommends sending credentials over an unencrypted connection.
Fill in both Username and Password. Leaving Username empty tells Sumezi to skip authentication entirely — that only works against a server explicitly configured to accept mail without login, which none of the providers above are.
Your password is stored encrypted. Once saved, the field shows a row of dots — leave it as-is to keep the existing password, or type a new one to replace it.
Step 3 — Send a test email
Save your settings, then click Send test mail. Sumezi sends a real test message through the connection you just configured — to your own account's email address, not to a subscriber. The status line updates to Connected or Test failed, and the result is remembered the next time you open this page.
Test failed? See Fixing deliverability errors for what each SMTP error message actually means and how to fix it.
Sending from your own domain
Connecting SMTP controls how mail is sent. To have it authenticated as coming from your own domain — for better inbox placement and your own sending reputation — add SPF, DKIM and DMARC records for your From email's domain. See "Verify your own sending domain", and check the status under Settings, Deliverability.