Top disposable email addresses

Everyone knows that some of the email addresses on your opt-in list will stop functioning with time. When someone changes job, for example, their work account gets deleted and future emails to that address bounce back as undeliverable.
It's an email marketing fact of life.
But nobody expects addresses to go bad in around 15 minutes. But that's happening more often with the growth of disposable email addresses. Here's what you need to know...
What are disposable email addresses?
The term "disposable email address" refers to addresses that have no long-term value to the owner and are easily discarded.
They are used in submission and sign-up forms when the address owner is skeptical of the trustworthiness of the website requesting the address, and/or is concerned about subsequently receiving spam or unwanted email from that source.
A different disposable address is used for each submission or sign-up form. So if you sign-up to newsletter X using a disposable address, then that email address would never be submitted elsewhere.
Semi-permanent disposable email addresses
Semi-permanent disposable addresses are intended for permanent use, but are easily closed down at no loss to the address owner.
If the owner ever wants to cease getting email from a store or site, they simply discard the unique email address they used at sign-up. Since the address only gets email from that single source, its loss doesn't affect the owner's email communication with anyone else.
People often use such disposable addresses to control spam and unwanted email. Say I sign up to a store's newsletter but find the material they send useless. I could unsubscribe, but if I don't trust them to honor my request, I can simply discard the unique disposable email address I used for that sign-up.
Equally, if I find other sites or individuals sending me email using that unique address, then I know that this address was sold or otherwise passed on to a third party. I can save myself a junkload of spam by abandoning the account. None of my other email is affected.
Temporary email addresses
Temporary addresses are identical to the semi-permanent disposable email address with one difference: they expire automatically without the owner needing to do anything. The temporary address might, for example, "self-destruct" fifteen minutes after its creation, or a month after creation, or "after receiving five emails."
These addresses are typically used when the owner needs an email address to complete a transaction, but does not want any further emails from the transactional partner and does not trust them with a more permanent address.
So the owner could submit a temporary email address on a form giving access to a company's white paper. With a 15 minute lifespan, the temporary address is active long enough to receive the email with the white paper link. But any further emails from that company would bounce as undeliverable.
Disposable address services
Many services make these kinds of addresses available to Internet users, often for free. Typical examples include SpamGourmet and Mailinator.
Some of the more popular webmail services also support disposable addresses. Gmail, for example, allows you to set up as many alias addresses as you like. When you no longer want to read emails sent to a particular alias, you can simply have them redirected to the trash folder.
Disposable addresses and email marketing
The semi-permanent disposable email addresses are not a huge issue for email marketers. If you're not selling or passing on addresses and if you're delivering valuable, relevant emails (both of which are recommended practices anyway), then a disposable email address is as good as any other.
If you are selling on addresses or sending rubbish email, you have bigger problems to worry about than disposable email addresses.
Temporary email addresses are another issue. They will go inactive, irrespective of your email marketing practices. The main issue here is the opportunity cost. Obviously, you have no chance to develop an email dialog / relationship with a temporary email address. And dead addresses mess with your statistics.
There are, however, various ways you can discourage their use.
You can reject form submissions that contain temporary addresses. Lists of temporary email address domains are apparently available for exactly this purpose.
The blacklist approach is short-term. It doesn't address the reasons why people use a temporary email address. Nor does it seem likely to encourage people to resubmit with a more permanent email address. Nevertheless, it's an option which is widely used.
A longer-term approach is to tackle the reasons why people use temporary addresses. People do so because they don't trust you to respect the privacy of their email address. Or because they object to having their goal (a purchase, a download) tied to a subsequent and compulsory stream of emails they simply don't want.
So you need to do three things:
1. Demonstrate your trustworthiness
This concerns issues such as the overall design of your website, presentation of your business, reputation management etc. But thinking specifically of sign-up forms and pages:
Include obvious links to privacy policies and ensure that these policies are customer friendly.
Include reassuring statements on privacy, such as "we will never rent, sell or pass on your address to others."
Ensure full contact details and information on your business are available (it's hard to trust an anonymous website).
Post relevant privacy, security and email certification seals.
Post customer and subscriber testimonials.
(See more sign-up form tips here.)
2. Only send subsequent emails that are truly necessary to complete the transaction...
The use of temporary email addresses is partly through the fear of the unknown. Let people know exactly what emails to expect (and why they are necessary / important / useful) and they are more likely to trust you with a "real" email address.
3 ...and provide a voluntary opportunity to grant permission for the other kinds of email you might also like to send.
Which is another way of saying, practice strict permission-based email marketing. If you accept that the only useful email address is one given with explicit permission for sending subsequent emails, then you want to do this anyway.
The key here is to make the benefits of your emails clear to the prospective recipient.
Websites and address list owners that have treated privacy and permission issues with disdain mean disposable email addresses are now a fact of email marketing life. The above tips should help minimize the "problem."