GreenArrow Email Software Documentation

Amazon SES Integration

This page lists special considerations when using Amazon SES as a relay server with GreenArrow. These steps are specific to Amazon SES and should be executed in addition to the steps required to setup an SMTP relay server

For more information on other steps necessary to integrate external relay services see Integrating with SMTP Relay Services

Amazon SES Email Verification

Amazon only relays messages that are sent from email addresses that have been verified.

Amazon SES requires the following email addresses to be verified:

  • The From address
  • The Sender address - this is only necessary if you plan to use a Sender header
  • The Return Path - also known as bounce address, SMTP FROM address and envelope sender

This documentation from Amazon has all of the steps necessary to verify the specific From and Sender email addresses.

Verifying the Return Path

Amazon SES does not recognize the VERP method GreenArrow uses to encode the variable part of the bounce address. This means that, to Amazon, every message that GreenArrow sends has a unique bounce address that needs to be verified.

Because of this, we recommend verifying GreenArrow’s Return Path address by verifying the whole domain you’re using in the Return Path address.

This documentation from Amazon has all of the steps necessary to verify a domain.

NOTE: If domain verification is not possible then there is a more complicated alternative method to verify the Return Path address (including GreenArrow’s VERP portion) using Amazon’s wildcard feature. This method is described in the last section of this document.

Set Up Amazon SES Email Feedback Forwarding

Amazon SES is the MTA handling the final delivery of your emails so all bounces and spam complaints will be directed back to them. By default, this leaves GreenArrow without any knowledge of a bounce or spam complaint ever happening.

If you would like GreenArrow to receive a copy of any bounce or spam complaints, you will need to enable Amazon SES Email Feedback Forwarding.

Testing Amazon SES bounces and spam complaints

We recommend thorough testing of bounces and spam complaints after setting up Amazon SES as a relay.

To test the relay end to end, use the email addresses that Amazon publishes in the following article:

Testing from GreenArrow Studio

  1. Create a test mailing list
  2. Add the email addresses listed in the Mailbox Simulator article
  3. Create and send a campaign to the mailing list
  4. Check the statistics for the campaign, you should see bounces and spam complaints

Testing from GreenArrow Engine

  1. Send a message to the email addresses listed in the Mailbox Simulator article from your injection application
  2. Check the statistics for the send, you should see bounces and spam complaints

Sending Messages with Amazon SES Relay Server

Once the Relay Server is configured and the domains or email addresses have been verified with Amazon, messages can be sent over the new Virtual MTA.

It is important to set the Bounce and From addresses to one of the verified email addresses when sending over the new Virtual MTA.

Bounce address and From address in Studio

The Bounce address and From address are set on the section titled Delivery Settings, on Campaigns and Autoresponders.

These settings can also be udpated on Mailing Lists by clicking the Edit button at the bottom of the Mailing List page. Look for the CAMPAIGN DEFAULTS section.

Bounce address in Engine

In Engine, the bounce address can be set globally, in the Mail Class, and can be overridden through email headers.

  • Default Bounce Address: this is the bounce address that Engine uses by default. It can be overridden by Mail Class settings, and email headers. This email address is set in the Default Bounce Address section of the Incoming Email Domains page.

  • Mail Class: to override the bounce address on a Mail Class, choose the corresponding bounce address from the Bounce Address drop down list.

  • Email Headers: use the X-GreenArrow-BounceMailboxOverride email header to override the bounce address on each individual email.

Alternative Return Path verification method

Only use this method when domain verification is not possible

Only use the following verification method when domain verification is not possible.

GreenArrow encodes information about the subscriber and campaign in the Return Path, using Variable Envelope Return Path (VERP). To separate the base from the sub-address (the variable portion) in the localpart, GreenArrow uses a - character. Amazon recognizes + as the separator between the base address and sub-address.

By creating a bounce mailbox in Engine that ends with a + character, GreenArrow will set the Return Path to an address that has a + between the static and variable portions of the address, which will be a valid VERP address on Amazon. Then it’s just a matter of following the instructions to verify a single email address, with the bounce mailbox email address without the + sign.

Here are the steps:

  1. Create the bounce mailbox with the + at the end of the localpart (e.g.[email protected])
  2. Create an email forwarder with the localpart but without the + character that forwards to a mailbox that you can access - this is where Amazon will send the verification email (e.g. [email protected]).
  3. Follow Amazon’s instructions to verify the email address without the + ([email protected])
  4. Update the bounce address configuration for messages injected into Engine (see details below)
  5. Remove the forwarder after verifying the email address
  6. Thoroughly test bounces and spam complaints as explained in the section above.


  • Adding the new bounce address and the temporary email forwarder: amazon-aws-ses-bounce-forwarding-example

  • Optional: Updating the Server’s Default Bounce Address. Only recommended if all messages injected into Engine are going to be sent over the Amazon SES relay server: amazon-ses-incoming-domains-example amazon-ses-default-bounce-address

In the example above the bounce address is [email protected] (2) and the forwarder [email protected] (1) was created to forward Amazon’s verification emails to [email protected]. The forwarder can be removed after verifying the bounce address.

Amazon SES Reference

For more information about Amazon SES, configuration and integrations, please refer to their documentation page:

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