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SMTP relay service: SMTP+

A high deliverability SMTP relay built into MailUp

MailUp truly is your complete email delivery solution: an SMTP relay service is built right into your MailUp account, at no extra cost. Send transactional emails from your web application, ecommerce store, or even from your desktop, and enjoy high deliverability and detailed statistics.

  • Built-in SMTP relay A high deliverability SMTP relay right in your account.
  • No additional cost Make your transactional emails happy... and the CFO too!
  • Recipient- level stats Lots of reports and detailed statistics down to the recipient level

Why we added a hosted SMTP service to MailUp


Many companies have deliverability problems with emails sent from a Web site or Web application, and sometimes even with messages that they send from their desktop clients (e.g. Outlook). In addition, they'd like to know what happens to those messages.

SMTP+ answers both needs, providing high deliverability and tracking, down to the recipient level. In technical terms, it's called a "SMTP relay service": a hosted SMTP server, built right into your MailUp account. So now you can use MailUp not just to create and send email marketing campaigns and automated triggered messages, but also to send transactional and personal emails.

For example:

  • Configure your ecommerce store to use SMTP+ as the SMTP server to send transactional messages (e.g. order confirmation)
  • Set up your WordPress blog or Joomla Web site to send emails through MailUp
  • Configure your email client (e.g. Outlook) to send messages through SMTP+
Please note: if you use SMTP+ to send transactional or personal emails, you will need to set up a separate MailUp account so that it can be configured not to deliver messages to the "Promotions" tab in Gmail. For details on this, contact us.

SMTP+ is simple to use!

It's really easy to use. You just create a SMTP user in your MailUp account, and then add those credentials in the application that is sending the email (e.g. ecommerce system, CMS system, email client like Outlook or Thunderbird, etc.). SMTP+ will be the outgoing mail server.

Of course, it comes with many other features, including

  • Setup multiple SMTP+ users
  • Configure notifications (e.g. what happens when a message is not delivered)
  • Define how statistics should be aggregated (i.e. combine all messages whose subject contains "Order Confirmation" to see how often that kind of message is opened and/or clicked
  • Add SMTP+ as the outgoing mail server in your ecommerce, CMS, CRM, ERP system or individual desktop clients
SMTP statistics

Benefits of using SMTP+

  • Improved deliverability (% of messages that end up in the inbox vs. the spam folder)
  • Handles attachments up to 20MB in size
  • All recipients are stored in the List(s) used for SMTP+ in your MailUp account, thus building a contacts database that you can use for various things (e.g. important notifications or Holiday greetings)
  • View recipient-level statistics on messages sent: clicks, geolocation, device, etc.
  • View aggregate statistics by choosing an aggregation method (e.g. by sender, user, subject, dynamic subject, etc.)
  • Automatic bounce management (handling of delivery errors)
  • Automatic feedback loop management (handling of SPAM complaints)
  • Automatic unsubscribe management
  • Webhooks for near real-time notifications when certain events occur (e.g. notification to CRM system when an unsubscribe happens)
  • Automatically add a header and/or footer to all messages, if you wish (e.g. useful for some transactional emails)
  • Perform more sophisticated tasks by editing the X-SMTPAPI header
Detailed SMTP statistics

Hosted SMTP, perfect for Web apps

Now that it includes an SMTP relay service, MailUp becomes the ideal companion for your Web app.

  • Ensure messages get into the inbox!
  • Send messages through MailUp without any API integration
  • Flexibly configure the outgoing mail port to avoid any issues (e.g. Port 25 is blocked by your Web hosting company)
  • Automatically build a database with all recipients, useful for a variety of scenarios (e.g. to send a maintenance notification)
  • Automatic bounce, feedback loop, and unsubscribe management
  • Add an optional header and/or footer
  • Customize the X-SMTPAPI header for even more control

Cost of MailUp's SMTP relay service? Nothing :-)

That's right: we built MailUp to be "the" complete email delivery service. Therefore, we see SMTP relay as one of the features that must be there. So if you have a MailUp account, you can start using SMTP+ immediately. If you don't, sign up for a free trial and you'll be able to try it out.

If you're sending transactional emails, however, set up a separate MailUp account to ensure that they are not delivered to the "Promotions" tab. Contact us for details on this configuration.

Since MailUp is a multi-list environment, you will typically create one or more separate lists for SMTP+, so that it has separate statistics and settings. The outbound queue is shared with the rest of your MailUp account, but SMTP+ messages are by default set with a higher priority, so they go out before bulk messages (e.g. newsletter) that are already in the queue. In addition, you can further configure the priority settings for more control.