While we can ensure that the emails are sent to the recipient, whether or not the recipient accepts the email is out of our control. There are several reasons why emails our may be flagged as Spam, including:
1) When the recipient is using a corporate email, it is likely being marked as spam due to the internal firewall policies that they have set up. It's best to have the company's IT team whitelist our IP addresses. However, this may not always work as companies often have cascading security settings, meaning that the likelihood of an email reaching the CEO is less than when trying to reach someone in the marketing department.
2) When emailing a user with a personal email like a Gmail account, emails are handled differently due to the volume of emails that these domains receive. They generally do a decent job at filtering through the incoming messages, but there may be some exceptions, and in those cases, they will need to click the Not Spam button, which would move the email out of the Spam folder and prevent future emails from being flagged. The user can also add firstname.lastname@example.org to their safe senders list.
3) Due to the number of emails we send per day, there may be some recipients that flag an email as spam, which can trigger a temporary spam listing. For example, if someone's platform sent out a message to 500 learners and 10 of them flagged the email as spam, then there is a chance that the IP addresses associated with that particular email gets temporarily added to a spam listing. However, since these listing are constantly changing, the ratio of emails not marked as spam versus the ones marked as spam ensure that the listing doesn't last long. Additionally, we utilize multiple IP addresses to minimize disruptions if one of them is flagged.