Unsubscribe Processing in Hurricane MTA Server

HMS can insert an unsubscribe link and/or a List-Unsubscribe header
(mailto and/or http) in your outbound messages. These mechanisms are
integrated with the suppression system in HMS so that, if properly
configured, unsubscribed addresses are suppressed from future
delivery. For more information on List-Unsubscribe, please see RFC2369
[https://www.ietf.org/rfc/rfc2369.txt].

Adding an unsubscribe link and/or List-Unsubscribe header to your
outgoing email messages can help your reputation and may help to keep
you compliant with regulations that may require certain unsubscribe
features in your messages. A visible unsubscribe option gives the
recipient a friendlier alternative to clicking the spam button which
would likely cause more damage to your reputation and deliverability.
In addition, more and more mailbox providers look for unsubscribe data
when examining messages and may view the inclusion of an
easily-accessible unsubscribe link or header as a partial indicator of
an email's legitimacy. Gmail, goes so far as to include instructions
by which senders can ensure that their link is displayed in the top of
their message menu bar.

ENABLING MAILTO LIST-UNSUBSCRIBE HEADER

The mailto List-Unsubscribe header may be added to your outbound
messages by following the instructions below.

STEP 1:

In the Account level Bounce Handling Options enable and configure
Bounce Handling and make sure to select the Auto Add & Process
List-Unsubscribe option as well as specifying the Recipient Address as
one of the pieces of tracking information to include in the Return
Path.

STEP 2

In the Account level Suppression List settings, specify a suppression
list for the Add Unsubscribes To option and also make sure to specify
that same list in the Check Against option, if you wish to suppress
unsubscribes.

This will add a List-Unsubscribe header to your outbound messages on
this account, that looks something like this:

List-Unsubscribe: <mailto:[encoded information]@[bounce domain]>

[encoded information]

This value is encoded and will contain the recipient's email address
and other information.

[bounce domain]

This value is the Bounce Domain specified in the Account level Bounce
Handling Options configuration.

NOTE: If you also opt to add an http List-Unsubscribe header (see
below) then these two options will be combined into one
List-Unsubscribe header, so it will look different than above.

PROCESSING OF MAILTO LIST-UNSUBSCRIBES

When email is sent to the address in the mailto List-Unsubscribe
header, it will be processed by HMS as a bounced message with the code
of 6000. This event will also notify the suppression system that an
Unsubscribe has occurred for the original recipient's address. If the
suppression system has been setup properly (see step 2 above) future
emails to the recipient's address should fail.

ENABLING UNSUBSCRIBE LINK & HTTP LIST-UNSUBSCRIBE HEADER

STEP 1

Enable and configure the tracking server in the Open/Click Tracking
global settings. This turns on the tracking engine that will process
the unsubscribe requests.

STEP 2

In the Account level Other settings, enable the Unsubscribe Processing
option and specify a Tracking Server Host for this Account. This host
will be used in the List-Unsubscribe header.

STEP 3

In the Account level Suppression List settings, specify a suppression
list for the Add Unsubscribes To option and also make sure to specify
that same list in the Check Against option, if you wish to suppress
unsubscribes.

STEP 4

Insert the proper code in your message content where you want the
unsubscribe link to appear:

For text content:

This is my message.
{{HsUnsubscribe}}

Which will generate a link similar to:

http://[hms tracking server address]/unsubscribe?r=[encoded
information]

For HTML content:

<HsUnsubscribe>Custom Link Text</HsUnsubscribe>

Which will generate a link similar to this:

Custom Link Text.

In addition to generating the appropriate links in your message
content, these settings will also cause an http List-Unsubscribe
header to be added to your message. It will look something like this:

List-Unsubscribe:<http://[hms tracking server address]/unsubscribe?r=[encoded information]>

[hms tracking server address]

This value is specified in the Account level Other settings
configuration and should resolve to the public internet address of
your Hurricane MTA Server.

[encoded information]

This value is encoded and will contain the recipient's email address
and other information.

NOTE: If you also opt to add a mailto List-Unsubscribe header (see
above) then these two options will be combined into one
List-Unsubscribe header, so it will look different than above.

PROCESSING OF THE UNSUBSCRIBE LINK & HTTP LIST-UNSUBSCRIBE HEADER

When a the unsubscribe link is loaded from HMS, it returns a web page
similar to:

Thank You

Your request to remove your email address, john@socketlabs.com from
our mailing list has been received.

Please allow up to 48 hours to account for any currently pending
messages.

THIS EVENT WILL ALSO NOTIFY THE SUPPRESSION SYSTEM THAT AN UNSUBSCRIBE
HAS OCCURRED FOR THE ORIGINAL RECIPIENT’S ADDRESS. IF THE
SUPPRESSION SYSTEM HAS BEEN SETUP PROPERLY (SEE STEP 3 ABOVE) FUTURE
EMAILS TO THE RECIPIENT’S ADDRESS SHOULD FAIL.