Creating credentials

You need a valid login/password combination to use the SMTP API. These credentials have to be included in the SMTP handshake before you send the first message over the connection. SMTPeter supports both the "AUTH PLAIN" as well as the "AUTH LOGIN" authentication mechanism. The credentials must be sent over a secure connection, either you set up a connection using port 465 or you secure the connection with "STARTTLS".

The login/password combinations can be created and modified via the SMTPeter dashboard. You can create unlimited logins.

Credential settings

Because the SMTP protocol is not very suitable for passing parameters, SMTPeter uses an alternative way to specify the features that you like to use for the submitted messages. If you want to do this easily we recommend the REST API.

For every login/password pair that you create, you can enable or disable the required SMTPeter features. You can create multiple logins, and install a different feature set for each login. When you send out mail, you use login/password combination that supports the features that you need.

  • modify hyperlinks to track clicks
  • modify image urls to track opens
  • do not modify links that would trigger scam warnings
  • change envelope address to collect bounces
  • modify html code to contain inline css attributes

The above list holds the properties that can be associated with a login/password pair. When you use the dashboard to create a login, you can select the features to use for that login.

Delivery Status Notifications

If you use the bounce-tracking feature, SMTPeter replaces the envelope address and delivers the mail using its own envelope address. The envelope address that the recipient sees will therefore be different than the envelope that you supplied. All bounces first end up at SMTPeter, before they are optionally forwarded to the envelope address that you supplied.

However, if you do not handover the bounce handling to SMTPeter, SMTPeter behaves as a normal MTA and sends back DSN messages to your envelope address if anything goes wrong.

SMTPeter also supports the SMTP DSN extension, meaning that you can pass parameters to the "MAIL FROM" and "RCPT TO" commands that control when and what kind of DSN messages you would like to receive.

More information



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