The methods that you use to build your contact lists, called address acquisition, are crucial to maintaining good list hygiene and IP address reputation.
Recommended acquisition methods
The most commonly used acquisition methods are listed by most desirable to least desirable.
Address acquisition - confirmed opt-in
Confirmed opt-in, which is known as double-opt-in or double-confirmation, is considered the gold standard by most email experts and ISPs. This method provides a low risk, high ROI method to reach contacts.
ISPs often block email that generates many spam complaints. Confirmed opt-in provides the best opportunity to gain and maintain a email list that is composed of recipients who actively consented to receive the communications. They expect the emails and are less likely to report them as spam.
When an ISP or filter vendor blocks a sender's email, a proof of permission is required, which cannot be provided if permission was not granted by using confirmed opt-in. ISPs and filters also can require a "repermissioning" pass, which requires that all subscribers be offered the chance to opt out or to remain subscribed. These steps can be disruptive and can be avoided by using confirmed opt-in from the start.
How it works
- A prospect submits an email address in a website or form.
- You send a confirmation email to the provided address. The email contains a link, which must be clicked to confirm consent, and contains information that sets the recipient expectations about email frequency.
- Recipients who do not click to opt in receive no further email from that sender.
Limitations and advantages
This method requires more work and investment than single opt-in or opt-out, but you create a higher-quality contact list.
- This method increases the credibility and reputation of the sender.
- When you treat contact with respect and set clear expectations about email frequency, your contacts are less likely to report your email as spam or unsubscribe.
- Happy subscribers are more likely to remain loyal and make purchases.
- Due to an ongoing and widespread problem, it is recommended that you use CAPTCHA, a free service, to secure your web forms. Confirmed opt-in forms help mitigate the risk because bots use unsecured forms to sign up thousands of email addresses, resulting in what amounts to a denial of service attack.
If you use a website or online form to collect email addresses, use a check-box that a prospect must select to be added to a marketing program. Do not use pre-checked boxes. This practice is generally considered duplicitous and confusing. People do not notice the check-box and are surprised and angry when they receive marketing email that they did not expect. They might report the mail as spam and cause IP reputation and branding degradation.
Address acquisition - single opt-in
Single opt-in is the most common method for address acquisition and is the absolute minimum standard.
How it works
With single opt-in, a prospect grants a sender permission to send them email marketing. This permission is usually granted when the prospect submits an email address in a web form or in-store sign-up.
While it is possible to run a successful email campaign that uses this method, it can cause problems.
- It is impossible to know whether the recipient truly wants to be added to a marketing list without a confirmation.
- It is impossible to set the recipient's expectations, which can lead to increased spam complaints and blacklisting if the address is a spam trap.
- Unconfirmed email addresses can be incorrect or maliciously used.
- Incorrect addresses cause high bounce rates, which can provoke ISP-issued blocks, loss of IP address reputation, or both.
- Malicious submission of known spam traps can cause problems with delivery and reputation if the owner of that trap takes action.
- People often use throw-away addresses, expired addresses, or addresses that do not belong to them to get what they want from a website and to avoid being added to marketing lists. These addresses can poison a email list, which can result in varying negative and expensive consequences.
- Lists that use such address collections methods often result in some or all the following issues:
- When recipients do not click, open, or engage with an email, ISPs can flag the sender as a problem.
- Expired addresses cause high bounce rates.
- Addresses that belong to people who are not expecting the email causes high complaint rates.
Alternative ways of collecting email addresses
When you collect email addresses by telephone, in-store sign-ups, conferences, fishbowls, and webinars, you risk list contamination. Email addresses that are collected by these methods must be manually transcribed, which increases the chance of human error.
People also might provide addresses that are not theirs or are throw-away addresses. The best practice for this method is to send a confirmation email to the prospect to obtain official, recordable consent. This method eliminates incorrect addresses and ensures that the prospect wants to be added to a marketing list. To minimize complaints, the confirmation email must contain a reminder of where and when the address was collected.
Metrics used to determine IP address and domain reputation
Address acquisition - opt-out
Opt-out has a deleterious effect on IP address and domain reputation and causes problems with successful email delivery. Do not use the opt-out method for address acquisition. Opt-out includes the use of purchased or rented email lists and addresses that are harvested from the web.
How it works
Opt-out operates on the assumption that permission can be gained after the fact. Marketers send email to contacts who did not grant permission to send them emails. Contacts are expected to opt out (and not complain) if they do not want to receive emails from the sender. Contacts who do not opt out are assumed to have granted permission to receive emails.
- Opt-out places the burden of permission on recipients.
- Opt-out causes high bounce rates and spam complaints.
- Opt-out causes lack of engagement to soar, leading to a degradation in IP reputation.
As a result, ISPs place email in the bulk folder or block it, which requires manual intervention to resolve.
One of the most painful and expensive possible consequences of the opt-out method is a listing by Spamhaus SBL Advisory. Many ISPs and businesses use Spamhaus data to generate their blocklists. The Spamhaus stance on the opt-out method and the use of a purchased or rented list is clear: Opt-out should not be used.
For more information, see Spamhaus Email Marketing FAQs.
Disallowed address acquisition methods
Buying, renting, e-pending/appending, and using co-registration/affiliate lists greatly increases the risk of triggering spam traps. Many of the sources that provide co-registration/affiliate marketing services harvested the addresses or purchased the lists from other unreliable sources.
In accordance with industry best practices, we strongly recommend that you do not use any of these methods of address acquisition.
In marketing terms, "appending" is the practice of taking demographic information that is known or assumed to be related to a customer and matching it with other data. The terms e-pending and appending are used interchangeably.
- It is the position of MAAWG that e-pending/appending is an abusive practice and runs counter to all MAAWG values.
- Spamhaus's position aligns with MAAWG's position: Using an e-pending list is risky.
Buying and renting lists
When you buy or rent an email list, you do not have the consent of the recipients to send them email. Permission is not transferable from the source of the list acquisition.
Using such lists can damage your brand reputation and deliverability due to generated complaints and possible spam trap hits.
Harvested emails are collected by methods such as scraping websites and forums.
Harvesting emails is universally recognized as a bad practice. This method provides no way for recipients to opt in, and typically causes serious blocking and delivery issues for senders.
It is also important that you maintain records during the acquisition process and retain the records afterward.
Keep records of the following information:
- Date and time of contact
- The method that was used to obtain the email address
- The IP address that submitted the email address
If an email is blocked and requires manual intervention to resolve, ISPs and blacklists often demand proof of permission. Without good records, such proof is impossible to provide and the resolution might take longer.
For more information, see the following websites: