Skip to main content

Adjusting your Client Mail Application

Last updated March 2020


"How do I send email?" Many companies ask this question. Enterprises of all kinds need to send email, but few know where to even start. Whether you are sending a few transactional messages or managing high-volume marketing campaigns, Momentum easily integrates with your new or existing applications. It combines sending with real-time reporting and customer engagement data to meet your messaging needs.

Momentum accepts mail for delivery using SMTP (Simple Mail Transfer Protocol) or HTTP (Hypertext Transfer Protocol). When using SMTP, Momentum presents itself exactly as any other message transfer agent (MTA). User-level, client mail applications combine recipient list, template, and content into fully formed messages, conforming to the RFC 2822 standard, and send these messages to Momentum, which relays the messages ultimately to the recipients' inbox. By default, SMTP uses TCP port 25 for communication from the client mail application to a MTA.


To inject messages using SMTP, you will need existing generation or mail merge software that creates an email for delivery. The information provided in this section is intended as an introduction. However, a general knowledge of your existing client mail application is required.

The following examples provide instructions to transition from your existing Postfix or Sendmail MTA to Momentum.

Example 1:

If your application is already using SMTP to send messages directly to your existing MTA, simply adjust your application to send the messages to your Momentum server.

Common SMTP libraries include JavaMail (Java), Net::SMTP (Perl and Ruby), smtplib (Python), and (C#).

Example 2:

If you have some management code that needs to use the local server's "Mail" function:

  • If you are using Sendmail, edit the /etc/mail/ file to add a "smart-host" definition.


  • If you are using Postfix, edit the /etc/postfix/transport file to add an smtp relay definition.


  • Apply the changes and restart the local mail services.

  • Execute the management code as normal.

The mail will route to Momentum for delivery.

Was this page helpful?