Email marketing deliverability is the ability to send emails to database users and have them delivered to their inbox. In addition to the ability to send the emails, you also have to see the location of the inbox, that is, it will not be the same to receive the emails in the main tray, in the promotions tab or in the spam folder.
This is a critical factor to be able to measure the success of an email marketing campaign, for example, if a high percentage of the emails we send goes directly to the spam folder, this will directly affect the performance of the campaign.