Opt-Out Domain & IP Address Management Best Practices

Selecting the best strategy to manage the Opt-Out process in your email program.

What are Opt-Out Domains & IP Addresses?

Among the many laws and regulations impacting email marketing around the world, one common aspect in many instances is the requirement that every email sent must include a way for recipients to Opt-Out of receiving future emails from the sender. In the U.S., this is one of the core aspects of the CAN-SPAM Act that all email marketers are required to comply with.

Today, the industry-standard practice for providing this Opt-Out method is through the inclusion of a link in the email that directs recipients to a web page where they may submit a request to unsubscribe from future email campaigns. It may also link to a Preference Center, where the recipient can select which types of emails from the company that they wish to stop receiving (ex. marketing offers), while possibly continuing to receive other types (ex. a monthly newsletter).  

Like any web page, every Opt-Out Page or Preference Center Page is located on a specific web domain and associated IP address. Within OPTIZMO, these are our clients’ Opt-Out Domains and IPs, which are a part of every SUPPRESS account. Maintaining their security and consistent operation is vital for companies to ensure the uninterrupted operation of their email compliance program, which is why we provide an easy way for our clients to manage their Opt-Out Domains and IPs from within our platform. This includes the ability to easily implement domains and IPs that they have registered and acquired themselves or taking advantage or our Managed Domain and IP Service, through which OPTIZMO takes on the heavy lifting of obtaining and provisioning Opt-Out Domains and IPs on our clients’ behalf.

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How Opt-Out Domains & IPs can be Compromised

There are a variety of reasons that an Opt-Out Domain or IP Address might be compromised in a way that causes it to be flagged by an email industry blacklist. The blacklists are compiled by various industry organizations as a way of combating malicious email. While domains and IPs involved in the Opt-Out process are inherently designed to help email marketers run compliant campaigns, they can still end up on an industry blacklist for a variety of reasons, either warranted or unwarranted.

Domains may sometimes be added to a blacklist entirely in error and in other cases they may relate to activity on the part of a Mailer that the compiler of the blacklist believes to be non-compliant. 

Whatever the cause behind having an Opt-Out Domain or IP Address added to an industry blacklist, the issue can have various negative impacts on the Advertiser’s email program. It is important to note that having an Opt-Out Domain or IP Address appear on a blacklist will not in any way impede the function of the Opt-Out Link. However, there is a strong belief among many email marketers that having an Opt-Out Domain appear on an industry blacklist may negatively impact their campaign deliverability. While there is some debate in the industry as to the extent of this negative impact, numerous Mailers prefer not to run campaigns if the associated Opt-Out Domains have been blacklisted. So, whether or not the impact on deliverability is significant, if Mailers won’t run an affected campaign, there can be a very real impact on overall campaign performance.

OPTIZMO’s Guide to Opt-Out Domain and IP Address Best Practices

Over the past 10+ years, we have received numerous requests from clients for advice on how best to set up a strategy to manage their Opt-Out Domains and IP Addresses. So, we decided to collect this information into a set of best practices to help all of our clients select the best strategies to manage these foundational aspects of their email compliance programs. The guide below provides a great deal of information, based on our experience, of the advantages or different approaches and tactics around this process, all based on the specific needs of each client.    

Interested to learn more about managing your Domains & IPs through OPTIZMO? Contact your OPTIZMO rep or click the button below.

Opt-Out Domain & IP Address Management Strategy

It is not uncommon for Advertisers to use a single shared Opt-Out Domain across many or all of their mailing partners, as this is the most straightforward and simple process. (In this scenario, each Mailer still has a unique Opt-Out Link, but all links are based on a common domain.) While this setup is the simplest, there are many advantages to taking a more security-conscious approach. Having a functioning Opt-Out Link (associated with the Opt-Out Domain) is vital to effective email compliance and one way to ensure the security of the Opt-Out Link is to protect it from any potential 3rd party influence or compromise.

In the scenario of a single Opt-Out domain being shared across all of an Advertiser’s Mailers, a compromised Opt-Out Domain can have a detrimental effect on overall campaign performance, as it affects all Mailers at the same time. With this in mind, many Advertisers employ a more granular Opt-Out Domain and IP strategy, where multiple Domains and sometimes multiple IP Addresses are distributed across their Mailers in order to reduce overall risk of potential impact from 3rd party influence, as well as lessen the impact of having any single Domain or IP Address become compromised. The degree of diversity they select is based largely on the makeup of their affiliate email program and their general policies and philosophy around risk management. 

There are two major factors in determining how many Opt-Out Domains and IP Addresses you may want to use within your email program: Level of risk tolerance and the size of your email affiliate program.

Level of Risk Tolerance

In general terms, the levels of risk tolerance toward potential Opt-Out Domain and IP Address compromise can be categorized into three levels.

Low Risk Tolerance – Companies that want to take multiple steps to limit the potential of having all of their Opt-Out Domains or IP Addresses compromised by a single blacklisting issue. Companies in certain verticals (finance, insurance, etc.) where data security and brand safety are always a particularly high priority may be more likely to fit into this category, but any Advertiser may choose to take this approach. 

Medium Risk Tolerance – Companies that want to avoid the impact of potential blacklisting or other potential issues affecting their Opt-Out Domains and IPs, but balance that goal against other factors (program complexity, cost etc.) and are looking for a middle-ground solution.  

High Risk Tolerance – Companies that for various reasons are not particularly concerned about potential issues around their Opt-Out Domains or IP Addresses. It may simply be that their affiliate email programs are fairly small, with very few mailing partners or they may have never encountered a blacklisting issue previously, so it hasn’t created a concern to date.

Email Affiliate Program Size

Along with a company’s level of risk tolerance for potential Opt-Out Domain compromise issues, there is one other major factor in determining the appropriate Opt-Out Domain and IP Address management strategy – the size of their affiliate email program. 

Larger Affiliate Program (100s of Mailers or more) – In this instance, it can be more challenging to implement a solution delivering the lowest risk, since it could require an extremely large number of Opt-Out Domains and IPs, which can be complex to set up and manage if the company is self-managing that process, rather than using our Managed Domain & IP Service.   

Medium-Sized Affiliate Program (10s of Mailers) – This group can likely consider implementing any of the Opt-Out Domain setup options, as all of them may be feasible based on the level of complexity involved. So, their level of risk tolerance is likely to be the deciding factor in their approach to managing their domains and IPs. 

Small Affiliate Program (10 or fewer Mailers) – Companies with smaller email affiliate programs also have the options of exploring any of the setup options, because none is likely to be either overly complex or costly, even at the lowest risk option.


Number of Mailers per Opt-Out Domain & IP Address and Other Approaches 

Opt-Out Domain Setup Options

Controlling the Number of Mailers per Domain

1-to-1 Domain to Mailer 

This involves setting up a unique Opt-Out Domain for each Mailer. It represents the highest level of security from compromise for your entire email program. If any single Mailer encounters an issue with their Opt-Out Domain being compromised, it will have no impact on any other Mailer in your program.

This level of security is typically appropriate for companies that fit one or more of the following criteria:

    • Extremely low risk tolerance toward potential blacklisting or other Opt-Out Domain compromise.
    • Running a small to medium-sized, tightly managed email affiliate program, with a limited number of Mailers. 

1-to-Several Domains to Mailers

In this scenario, Mailers are put into small groups, and each group is assigned to a different Opt-Out Domain. (Please note that all Mailers use individual Opt-Out Links in any of these scenarios. This only relates to the number of Opt-Out Domains being used.) 

A variation of this level of security can be appropriate for the vast majority of companies, with the size of each Mailer group being determined by a combination of:

    • The size of the email affiliate program.
    • If the company wishes to be somewhat more or less risk-averse. 

1-to-Many (or All) Domains to Mailers

Under this setup, the Advertiser has only one Opt-Out Domain to use for all of their mailing partners. 

This setup is generally not recommended as a best practice, unless the Advertiser:

    • Has a very small email affiliate program (just a few Mailers at most), and
    • Has relatively limited concern about the risks of having an Opt-Out Domain become compromised. 

A Cohort-Based Domain Setup Strategy

A Cohort-based domain strategy involves organizing certain sets of Mailers into specific groups (or Cohorts) based on a variety of possible rationale. Each Cohort Group is then assigned its own Opt-Out Domain. This approach can most easily be applied to a Medium or risk tolerance strategy, as it is focused on mitigating potential issues related to Mailer activity and its potential impact on the Opt-Out Domain, while not entirely isolating each and every Mailer.

Here is how one possible Cohort-based strategy could be structured.

Cohort 1 – New Mailing Partners

All Mailers that are new to the Advertiser are initially assigned to this Cohort. The idea being that this isolates all Mailers who have no history with the Advertiser into one group, so if any turn out to have issues, it won’t impact the more established Mailer groups. If an Advertiser is regularly onboarding new mailing partners to their program, the makeup of this group may change fairly regularly, as new Mailers are tested and those that are successful are shifted to other Cohorts of ongoing partners.

Cohort 2 – Higher Risk Partners

This group is made up of Mailers whose performance is acceptable to the Advertiser, but who also may have a higher propensity for potential issues. This could be due to any number of reasons, such as a Mailer who has had a past blacklisting occurrence, one with higher than normal opt-out rates, or simply the makeup of their email lists are more fringe to the Advertiser’s target audience. So, these Mailers are seen as higher risk, but are still meeting the Advertiser’s requirements of mailing partners. It may be that after a time period with no issues, a Mailer might be removed from this group.

Cohort 3 – General Population

This includes Mailers who fall into an average risk category for the Advertiser. It often makes up the bulk of the Advertiser’s mailing partners. They have established themselves as reliable mailing partners, with fairly limited risk and solid performance overall. Mailers may stay in this Cohort for a long period and would only shift to another, if their performance changes.

Cohort 4 – High Quality/Low Risk

Finally, a 4th group is made up of Mailers with the highest quality/lowest risk. These may also be an Avertiser’s top performers, but in general they are the most trusted mailing partners and considered the least likely to create any issues. They may have the highest quality email list(s), simply generate the fewest spam complaints, or have the lowest opt-out rates. This also might be a group that the Advertiser trusts to test new campaigns before other Cohorts. 

Opt-Out IP Address Setup Options 

Similar to Opt-Out Domains, the most risk-averse strategy involves using a large number of IP Addresses across your Mailers. This strategy can be challenging for companies to set up and manage, as managing IP Addresses over time can be more complex than Domain Names. However, OPTIZMO makes it easy to enable the highest level of IP Address isolation, through our Managed Domain options, with a Premium Domain.

1-to-1 IP Address to Mailer

Similar to the 1-to-1 setup for Opt-Out Domains, this is the most risk-averse option, where a unique IP Address is assigned to each Mailer and its associated Opt-Out Domain. 

This can be set up within SUPPRESS by adding a Premium Opt-Out Domain, which is assigned to a Dedicated IP Address and then assigning each Premium Domain to one Mailer.

1-to-Few IP Addresses to Mailers

Similar to the 1-to-1 or 1-to-Several setups for Opt-Out Domains, this is the most risk-averse option, where a limited number of Mailers and their associated Opt-Out Domains are assigned to a single IP Address. 

This setup is available within SUPPRESS, by adding a Premium Opt-Out Domain to your account and then assigning it to a select group of Mailers. This then puts all those Mailers on a Dedicated IP Address.

1-to-Many (or All) IP Addresses to Mailers

As with the 1-to-Many Domains to Mailers setup, this option appeals to Advertisers that don’t have significant concerns about potential compromise or only work with a smaller group of mailing partners.

There are various ways to set this up in SUPPRESS, with slightly varying levels of IP Address isolation. The most broad approach would be the standard setup in SUPPRESS with either a Complimentary Domain or a Basic Domain, each of which are assigned to shared IP Addresses with other clients and then assigning this Opt-Out Domain to all Mailers. I slightly more secure variation would involve setting up a Premium Domain for all your Mailers. This would put all your mailing partners on on IP Address that is not shared with any other clients.

Refreshing Opt-Out Domains and IP Addresses Over Time

One question that comes up from time to time is whether there is a need or benefit in updating Opt-Out Domains and/or IP Addresses after some period of time. In general, if an Opt-Out Domain or IP Address has not been compromised, it should continue to remain secure over time. However, there is an argument to be made that updating them from time-to-time, even if there have not been any recognized issues, is a good practice to reduce the risk of future compromise.  

There is no hard and fast rule on how often these updates should occur. It is best to consider them along with the regular process of adding new domains and IPs as your email programs grows and more Mailers are added to the mix. As you are adding more Mailers to your campaigns within SUPPRESS, look back at your existing Opt-Out Domains and IP Addresses. If you’ve been using the same initial domain and IP for one or more Mailers for over a year, you might consider switching things up with a new domain or IP Address.

In general, it is a best practice to review your current setup with Opt-Out Domains, IP Addresses and associated Mailers at least once a year, just to make sure the entire setup is lining up with your goals and general level of campaign complexity and risk tolerance.     


Naming Structure for Opt-Out Domains


How Should You Name your Opt-Out Domains?

Like any domain name you register, Opt-Out Domains can use a wide variety of naming structures and naming conventions. However, unlike the domain name of a company’s website, your Opt-Out domain likely has limited marketing value and there are reasons why it may make sense for it to be largely disconnected from your regular website domain or your brand in general.  

Using your Brand Name in your Opt-Out Domain (and why you may not want to)

    • The Opt-Out Domain has limited marketing value, because it will rarely be visible to the user (since the Opt-Out link will likely be connected to a button or text link in the email that says Unsubscribe).
    • If an Opt-Out Domain does appear on a blacklist for any reason, it is preferable if a company’s name isn’t actually in the domain. It also makes it easier to swap out with a new Opt-Out Domain that is also unrelated to your brand. 

Descriptive/Real Words vs. Random Characters in your Opt-Out Domain

    • There is no particular need for Opt-Out Domains to be memorable or even particularly recognizable for users, since they are generally only accessed through an Opt-Out button or text link in an email campaign. So, there is likely no impact on their usability whether they are actual words or simply random characters.
    • Using words like ‘opt out’ or ‘unsubscribe’ in the domain may actually make it more likely to be flagged on a blacklist, since it immediately is recognizable as being part of a marketing email. Logic would suggest that domains that seem to be associated with the Opt-Out process would be safer from blacklisting, as they are a sign of a company focused on sending compliant email campaigns. However, this does not appear to be the case.

With all this taken into consideration, the best practice for setting up your Opt-Out Domains is to use either random characters or words that don’t pertain to your brand, website, or the Opt-Out process itself. While this is certainly no guarantee that an Opt-Out Domain won’t ever be blacklisted, it does help reduce the likelihood of it happening based on the domain name itself. 


Benefits of a More Risk-Averse Opt-Out Domain & IP Address Strategy

While every Advertiser will determine the best approach to its Opt-Out Domain and IP Address strategy, there are definite benefits in taking a more risk-averse and security-focused approach. These benefits can extend beyond the Advertiser and brand to the mailing partners as well. Take a look at just a few of these key benefits.   

Benefits for Advertisers and Networks

Reduces Impacts Associated with Opt-Out Domain Blacklisting

If a blacklisting issue occurs on one Opt-Out Domain, the impact is contained to just the Mailer or Mailers assigned to the impacted Opt-Out Domain (i.e. the more domains the better). This means that impacts to the overall campaign are minimized.

Makes Tracking Mailer Activity with Regard to Blacklisting More Effective

With a limited number of mailers assigned to each Opt-Out Domain, it becomes much easier to determine which Mailer was using a domain that was compromised. This makes overall Mailer monitoring easier, more effective, and more actionable.  

Improved Campaign Deliverability 

Assigning fewer Mailers to each domain will improve overall campaign delivery in the event of any blacklisting issues, as the impact will be isolated to just the Mailer(s) on the affected domain.

Opt-Out Domains are Less Likely to be Blacklisted Overall

In general, by limiting the activity on each Opt-Out Domain, all domains may be less likely to catch the attention of the blacklist providers, since each domain is included in fewer campaigns and fewer emails in total.

Benefits for Mailers

Isolates Mailers from Each Other’s Activities

Mailers go to great lengths to keep their email activities separate from other Mailers in general. So, they will always prefer that if another Mailer’s Opt-Out Domain is compromised, it won’t have an impact on their deliverability or campaign performance in any way. In fact, this is a real value add for some quality Mailers when deciding to run an Advertiser’s campaigns.

Potential for Improved Overall Campaign Deliverability 

A main concern for Mailers about Opt-Out Domain blacklisting is that it may have a negative impact on their campaign deliverability, if the email includes a blacklisted Opt-Out Domain. The more isolated they are from the activity of other Mailers and the fewer blacklisting issues they run into, the less impact such issues can have on their overall deliverability.  

Opt-Out Domains are Less Likely to be Blacklisted Overall

As mentioned above, limiting the usage of each Opt-Out Domain may make it less likely for the domains to catch the attention of the blacklist providers. 

Next Steps

Determine Your Optimal Strategy for Opt-Out Domain and IP Address Management

After going through these best practices and recommendations, the next step is to evaluate your current practices around managing your Opt-Out Domains and IP Addresses and making sure it lines up with the goals and scope of your email program, as well as your general tolerance for the potential disruption caused by a future blacklisting issue. You may find that your current setup and process is already in line with your optimal strategy. If this is the case – outstanding! You are already set up and running in a way that properly aligns your Opt-Out Domains and IPs with your strategy and goals.

However, if you find that some changes to your current management process are needed in order to be in sync with your preferred strategy, you have a few additional steps to take. 

Consider the Most Effective Way to Implement your Strategy

You have options when considering how to best implement your enhanced Opt-Out Domain and IP Address management strategy. 

1.  You could obtain the necessary number of Opt-Out Domain names and/or IP Addresses on your own, through a domain registrar or other service. You would then need to set these domains up within SUPPRESS as new Custom Domains, managed by your team. However, this process can be very manual and puts the workload on your team from initial domain registration and setup, through renewals and monitoring of blacklists for those Opt-Out Domains in the future. Then, if the need arises to update domains or IP Addresses down the road (due to blacklisting issues or any other reason), that continues to be your team’s responsibility. 

2.  Alternatively, many of our clients simply rely on the OPTIZMO team to handle the majority of this potentially labor-intensive process by taking advantage of our Managed Domain Service. Through this service, our team handles Opt-Out Domain registration and IP Address provisioning and setup within SUPPRESS. OPTIZMO also proactively monitors these domains and IPs and alerts you if any appear on an industry blacklist, and can quickly switch out impacted domains or IPs with new ones to limit any impact to a short period of time. 

If you would like to learn more about our Managed Domain and IP services, simply contact your OPTIZMO rep or reach out to us at sales@nulloptizmo.com for more details. 

 OPTIZMO provides clients with an easy way to obtain and provision Opt-Out Domains within the SUPPRESS platform, where we take care of all the heavy lifting as a Managed Service. This enables clients to easily implement a Compliance Isolation process, to secure their Opt-Out Domains and IPs from outside influence. For pricing details, contact your OPTIZMO account rep or simply reach out to us at sales@nulloptizmo.com.