I think people generally assume that email is just automatically delivered to the address that we send it to. My research tells me this is not true. As I stated in the Introduction, about 20% of all opt-in emails never make it to the inbox. You'll notice that I specify opt-in emails. In this book we are specifically talking about emails that are newsletters, so that is what weāre mostly interested in. But as an aside, studies show that newsletter delivery generally is not 100%.
When we're talking about deliverability we need to be clear what is meant by that word. A quote from Email Delivery Best Practices Guide ā a part of the MailChimp help documentation.
āSuccessful email delivery is your message arriving in the inbox of the recipient as intended. Email delivery failure is when your message is either validated to the junk or spam folder, or completely blocked by an Internet service provider.ā
What are bounced emails? A bounced email is one that isnāt successfully sent for a variety of reasons. Bounces can be classified as either soft or hard bounces. A hard bounce happens when an email is sent to an email address that doesnāt exist for some reason. Either it did and has since been closed or there is an error in the email address resulting in no known address. Thereās no easy recovery from a hard bounce other than contacting the person and requesting a new email address.
A soft bounce, on the other hand, can be easier to recover from. A soft bounce can just be a notification that there is a bit of difficulty in delivery but it will resolve itself.
There are a variety of reasons for a newsletter to bounce - hard or soft. Here are the most common ones:
1) A non-existent email address - if an email account has been closed or deleted the email will get a hard bounce. This type of bounce occurs when subscribers close old email accounts or move jobs causing their work email address to be deleted. It is also possible that people give a false email address or make a mistake when submitting at a live event - perhaps filling out a paper form (although double opt-in will eliminate those errors)
2) Undeliverable email - notes in this category indicate that either the recipientās server is temporarily unavailable or was overloaded or under maintenance. This type of bounce may be recoverable from if the issue is temporary - as in maintenance - but if the email server is gone for good, the email will then hard bounce.
3) Mailbox is full - this is a common error for limited free email accounts. There is a cap on storage and the person has exceeded it. This can mean that the person has abandoned the address or they have maybe gone on holidays and will empty the mailbox when they get back.
4) Vacation/out of office reply - Unlike other bounce categories, these emails are usually delivered. Of course, someone who never returns from a vacation, will eventually be considered to be a hard bounce.
5) Blocked email - if your email address, or your email marketing serviceās email address has been blocked by the recipientās email program, the block needs to be requested to be removed. It isnāt unusual for government or schools to have really tight reigns when it comes to receiving emails resulting in this type of a bounce.
6) Denied by the Firewall or Spam Filter - as weāll learn in this book, the recipientās email provider may decide that your note doesnāt pass muster and is denied entry. This will result in a bounce as well. Sometimes the recipient adding your email address to their contact list will help, but there could be something in one newsletterās content that the firewall or spam filter finds objectionable and that situation can change for the next newsletter.
Bounce rates should be monitored - sudden increases should be paid attention to rather than accepted as normal. There will always be a certain number of bounces from a large list, but sudden changes are not normal.