[Also applies to v8]{class="badge positive" title="Also applies to Campaign v8"}

Sending with the Enhanced MTA sending-with-enhanced-mta

The Adobe Campaign Enhanced MTA (Mail Transfer Agent) provides an upgraded sending infrastructure allowing for improved deliverability, reputation, throughput, reporting, bounce handling, IP ramp up and connection setting management.

It is implemented to improve scalability, increase delivery throughput and help send more emails faster. This is achieved with new adaptive delivery techniques that alter email sending settings in real-time based on feedback from Internet Service Providers.

The Adobe Campaign Enhanced MTA is only available for Campaign Classic hosted or hybrid customers. Campaign Classic on-premise installations cannot be upgraded to use the Enhanced MTA.

If you were provisioned a Campaign Classic instance after September 2018, you are using the Enhanced MTA. For all other Campaign Classic customers, see the Frequently asked questions below.

The Enhanced MTA implementation may impact some of the existing Campaign functionality. For more on this, see the Enhanced MTA specificities.

If you are an end user of Adobe Campaign and you want to know whether your instance has been upgraded to the Enhanced MTA, contact your internal Campaign administrator.

Frequently asked questions enhanced-mta-faq

Usage and benefits

What is the Enhanced MTA?

Adobe Campaign can now be upgraded to use a new MTA (Mail Transfer Agent) which runs SparkPost’s commercial email MTA called Momentum.

Momentum represents innovative, high-performance MTA technology which includes smarter bounce handling and an automated deliverability optimization capability that helps senders achieve and maintain optimal inbox delivery rates.

What are the benefits?

  • Adobe Campaign clients using the Enhanced MTA have seen a massive increase in overall throughput speed, and a significant reduction in soft bounces.
  • The Enhanced MTA uses the latest MTA technology to provide you with the optimal throughput speeds for your email delivery.
  • By adapting instantly and automatically to the feedback it receives, it also ensures more accurate and intelligent email delivery with real-time delivery data.

Can I use the native Adobe Campaign MTA and the Enhanced MTA at the same time?

No. Only the Enhanced MTA can be used for your email deliveries after your instance has been upgraded.

Upgrading to the enhanced MTA

What is required to upgrade to the Enhanced MTA?

If you were provisioned a Campaign Classic instance after September 2018, no action is required as you are already using the Enhanced MTA.

For all other hosted or partially hosted (hybrid) customers, the Adobe Campaign team will reach out to coordinate a date for migration and will provide details on the appropriate steps needed to migrate.

The Enhanced MTA is not available for on-premise installations.

What is the process to upgrade my instance to the Enhanced MTA?

The entire process for your hosted instances requires a few minutes of downtime. Adobe will monitor the email throughput and deliverability for up to 24 hours post-upgrade to assess any impact to your email deliveries.

In case any issues are discovered, Adobe can quickly and temporarily revert your instance back to the native Adobe Campaign MTA.

Currently, the Enhanced MTA only affects the email channel. Your push notifications and SMS deliveries will continue to use the native Campaign MTA and will not be affected in any way by the upgrade.

Do I need to go through IP warming again after upgrading to the Enhanced MTA?

No. Upgrading does not require switching to new IPs, so you can continue using your existing, warmed email IPs.

Will upgrading to the Enhanced MTA impact any campaigns or deliveries currently in progress?

For customers using Adobe Campaign transactional messaging functionality, any API calls to trigger an email will be queued during the very short upgrade downtime and will be attempted upon completion of the upgrade.

Enhanced MTA specificities enhanced-mta-impacts

New MX rules

The MX management delivery throughput rules are no longer used. The Enhanced MTA has its own MX rules that allow it to customize your throughput by domain based on your own historical email reputation, and on the real-time feedback coming from the domains where you’re sending emails.

For more on MX configuration, see this section.

Bounce qualification

The bounce qualifications in the Campaign Delivery log qualification table are no longer used for synchronous delivery failure error messages. The Enhanced MTA determines the bounce type and qualification, and sends back that information to Campaign.

The Enhanced MTA qualifies the SMTP bounce and sends that qualification back to Campaign in the form of a bounce code mapped to a Campaign bounce reason and qualification.

For more on bounce qualification, see this section.


A delivery cannot be stopped once it has been transferred to the Enhanced MTA - even though it is displayed with the Stopped status in Campaign.

Delivery throughput

The Campaign Delivery throughput graph will no longer display the throughput to your email recipients. That graph will now show the throughput speed for the relay of your messages from Campaign over to the Enhanced MTA.

For more on the delivery throughput, see this section.


The retry settings in the delivery are no longer used by Campaign. Soft bounce retries and the length of time between them are determined by the Enhanced MTA based on the type and severity of the bounce responses coming back from the message’s email domain.

For more on retries, see this section.

Validity period

The validity period setting in your Campaign deliveries will be used by the Enhanced MTA only if set to 3.5 days or less. If you define a value higher than 3.5 days in Campaign, it will not be taken into account.

For example, if the validity period is set to the default value of 5 days in Campaign, soft-bouncing messages will go into the Enhanced MTA retry queue and be retried for only up to 3.5 days from when that message reached the Enhanced MTA. In that case, the value set in Campaign will not be used.

Once a message has been in the Enhanced MTA queue for 3.5 days and has failed to deliver, it will time out and its status will be updated from Sent to Failed in the delivery logs.

For more on the validity period, see this section.


DKIM (DomainKeys Identified Mail) email authentication signing is done by the Enhanced MTA. DKIM-signing by the native Campaign MTA will be turned off within the Domain management table as part of the Enhanced MTA upgrade.
For more on DKIM, see the Adobe Deliverability Best Practice Guide.

Delivery success reporting

In the  Summary  view of an email delivery dashboard, the  Success  percentage starts out at 100% and then progressively goes down throughout the delivery validity period, as the soft and hard bounces get reported back from the Enhanced MTA to Campaign.

Indeed, all messages show as  Sent  in the sending logs as soon as they are successfully relayed from Campaign to the Enhanced MTA. They remain in that status unless or until a bounce for that message is communicated back from the Enhanced MTA to Campaign.

When hard-bouncing messages get reported back from the Enhanced MTA, their status changes from Sent to  Failed and the Success  percentage is decreased accordingly.

When soft-bouncing messages get reported back from the Enhanced MTA, they still show as  Sent and the Success  percentage is not yet updated. Soft-bouncing messages are then retried throughout the delivery validity period:

  • If a retry is successful before the end of the validity period, the message status remains as Sent and the Success  percentage remains unchanged.

  • Otherwise, the status changes to Failed and the Success  percentage is decreased accordingly.

Consequently, you should wait until the end of the validity period to see the final Success percentage, and the final number of actually Sent and Failed messages.

The table below shows the different steps in the sending process with the corresponding KPIs and sending logs statuses.

Step in the sending process
KPI summary
Sending logs status
Message is successfully relayed from Campaign to the Enhanced MTA
Success percentage starts out at 100%
Hard-bouncing messages get reported back from the Enhanced MTA
Success percentage is decreased accordingly
Soft-bouncing messages get reported back from the Enhanced MTA
No change in Success percentage
Soft-bouncing messages retries are successful
No change in Success percentage
Soft-bouncing messages retries fail
Success percentage is decreased accordingly