You have set up an email list with that service everyone said would be great for you. You created perfect opt-in gifts. You built great looking forms, and alluring landing pages. You wrote a blog post to tell about your new opt-in and shared the living daylights out of it. Then, something awesome happened. People subscribed. Not just one person, not only two. But hundreds of people.
However, you soon notice they didn't actually ever confirm their email addresses. You just have now a list of unconfirmed emails laying around. What the what?
There are many reasons why this might happen. The people subscribing may not receive the confirmation emails. Your subscribers may be widely spam addresses, filling any form on any website they find. Your subscribers may not understand that they must confirm their subscription, or they don't see the point in it.
Your unconfirmed subscribers are spambots
I've had spambot issues with my email lists before. Actually, I've noticed that if I add a form directly somewhere on my blog posts, the amount of spammy addresses subscribing suddenly grows. No matter if it's on top of the posts, on the sidebar, or on the bottom of them. The bots see a form, they fill the form.
Fortunately, spambots aren't that great with double opt-in. Years ago, I had a problem with MailChimp leaking spam addresses through despite the double opt-in, and I've heard people still have the same problems. But nevertheless, many unconfirmed emails on your list sound like a spam problem.
While it may be difficult to know which addresses are spam, you can start with making a quick checkup yourself. Do many addresses have different name than the name provided by the subscriber? Does the name provided by the subscriber include a multiple random looking numbers? Are the names or addresses otherwise odd, gibberish sounding, and suspicious looking? If you suspect the unconfirmed emails may not be what they seem, you can check their validity.
In case you have only few possible spam addresses to check, you can go to sites like Stop Forum Spam and search the address. If the address is found from lists like these, it probably belongs to a spambot.
Dozens or hundreds of email addresses require other kind of checkups. There are many services for this, many of them paid. However, they may also provide limited free checkups and trial accounts. The services include such as Neverbounce, Email List Verify, Email Verifier by Hunter, DataValidation, and much more.
Since these addresses are not confirmed, you don't have to worry. They aren't counted as subscribers, nor they receive your emails and count as bounces etc. in the future.
The reason to verify these emails is to find out if you have a spam problem, or if the problem is with delivery or people not knowing they should confirm their addresses.
Your confirmation emails are filtered
Very often, when subscribers don't confirm their email addresses to actually join your list, it is a matter of them not seeing your emails. Due to the nature of the confirmation emails, there's a chance they end up automatically marked as spam.
It's been estimated that the amount of spam emails sent every day is about 200 billion, which is most of emails sent. You see only a small portion of spam emails, because there are many countermeasures against them. Most of the spam appears to be filtered at different points of their lifetime. Not all spam even gets in anyone's spam box. It just kind of goes away.
Thus, your emails may get filtered before or after they land anywhere near your subscribers' inboxes.
If there's a persisting problem, you need to check if the domain of your email address is blacklisted. Blacklists work by identifying spammers by their IP address and email domain. There are multiple blacklists out there, utilised by different email providers and services.
You can make a search for "email blacklist" or "domain blacklist" to find websites that allow checking if your domain is in some of those blacklists. Those websites include such as Email Blacklist Check by MxToolbox and Domain Blacklist & Email Spam Check by UltraTools.
Sometimes your email list service may end up on those spam lists. This happens often if there are many spam complaints for any emails sent through the service, even if it has nothing to do with your emails. Email services know this can happen and keep an close eye on blacklists and work on resolving the problem when possible. This is also why email services aren't happy if your emails are marked as spam or there are other complaints.
Did you know that email providers and services, such as Gmail, can limit the amount of emails they receive from one domain or address? You may also be hitting a limit like this.
If many of your subscribers use Gmail addresses, there are different things that may cause your confirmation emails not to land their inboxes or even spam boxes. For example, if your domain is suddenly sending lots of emails to Gmail addresses, you may be hitting a temporary rate limit. That means, Gmail limits the amount of emails that will be received from your domain. After it becomes clear your emails aren't spam, the limit is lifted.
This is why it may be bad for your list to grow very fast. The sudden huge amount of emails sent from your domain can be seen suspicious by different email providers and services.
One simple thing you can do to help your domain to seem more legit, is to set up an abuse email address. That is, firstname.lastname@example.org, where example.com is replaced with your own domain (it can be a separate email, or a forwarder). Having this address working sends a message to email providers, services and blacklists, that you may not be a spammer.
Hopefully your email list service allows you to create a confirmation message/page, which is shown to subscribers right after they submit their information. In the confirmation message, you can ask your subscribers to add your email address in their contacts. This increases the chance the emails end in their inboxes, and is not filtered as suspicious. I also recommend adding a little note prompting to check the spam box or try to subscribe again, if the confirmation email doesn't arrive in due time.
Your subscribers just don't confirm
For some people double opt-in may seem like extra trouble. Others may not understand that they aren't subscribed to your list (and don't receive the gift) without confirming their email addresses.
There are many people out there who'd like to get the free gifts without subscribing to your lists. When subscribing, they may not be clear of the fact that they will also get your emails, and how often they get them. Seeing the confirmation email, they may decide against going through this trouble for the gift. You are better off without them confirming, really.
It's possible, your confirmation email or the confirmation message aren't clear enough. Either the subscribers don't realise they must click that link in the email to actually get the gift and get on your list. Or they don't understand why they must confirm in the first place.
For the confirmation message, before the information I suggested earlier, add a little text which asks the subscriber to check their inbox for the confirmation email. Remind also that only by confirming the subscriber can get the opt-in gift, and other content.
If you can, change the text on the confirmation link (it may be called and designed as button by your email list service), change it to say something like "Confirm and download the gift". This also works for drip courses, just change the wording to fit the purpose. This way, the subscriber will know they must click the link to get the gift.
Additionally, add a short text before the confirmation link. This text tells that the subscriber must confirm their subscription by clicking the link/button below, and that they will get whatever you have promised for them only after confirmation.
You can also add other information to this email, after the confirmation link. However, keep the information short and leave space between it and the confirmation link. Otherwise your subscribers may just see mass of text, and ignore the confirmation link altogether.
Don't panic, troubleshoot
Email lists can be frustrating. First nobody subscribes. Then everyone and their bot subscribes. Finally, something goes wrong.
Not getting people to confirm their subscription? Try finding out if the problem is with spam, if there are delivery issues, or if the subscribers just don't know they should confirm.
Of course, I recommend contacting the support of your email list service. Either way, troubleshoot before switching between tons of different email list services, spending lots of money, and creating new subscription gifts to replace the ones you think aren't working.