Checking bounces and complaints after a delivery
You cannot fully find out whether your newsletter has ended up in a spam folder. If a subscriber’s mail server accepts your newsletter, it may land in their inbox, or just as easily in their spam folder. Email Service Providers (ESPs) such as Laposta usually do not receive a notification when an email provider marks an accepted newsletter as spam. However, there are two signals you can see in the results of your campaign.
Checking soft bounces and complaints
If a subscriber’s mail server rejects your newsletter immediately upon receipt because it considers it to be spam, this counts as a soft bounce. You can find the email addresses involved in your campaign results via Results → Unsubscribes → Bounces. After six consecutive soft bounces, a subscriber is automatically cleaned: the address moves to the ‘cleaned’ tab and you can no longer email it.
In addition, a number of providers notify Laposta when a recipient marks your newsletter as spam themselves. These reports are listed in the results under Unsubscribes → Complaints. When such a spam complaint occurs, the subscriber is also automatically cleaned and you can no longer email them.
Why you cannot see what ends up in the spam folder
In theory, every accepted newsletter that has not been opened could have ended up in a spam folder: the number of accepted emails minus the number of opened ones. That only indicates a maximum, as by no means every unopened newsletter has been marked as spam. Unfortunately, there is no reliable way to find out how often this happens.
Email providers deliberately keep the exact workings of their spam filters secret so that spammers cannot bypass the filter. Furthermore, every spam filter works differently and often consists of a general component and a component tailored to the recipient. As a result, one person with a Hotmail account might receive your newsletter normally, while for another person with a Hotmail account it ends up in the spam folder.
So while you cannot measure how often your newsletter ends up in the spam folder, you can reduce the likelihood of it happening: