Inbox placement, also known as email deliverability, is whether emails land in the inbox or in the spam folder (or just not get delivered at all). For obvious reasons, businesses should care about whether their emails are making it to their final destination (to the recipient). Keep reading to learn more about this topic, and how email engagement plays a key role. 

Inbox placement includes three main scenario, depending on the recipient inbox:

1. Free inbox (gmail, yahoo, etc)

Use engagement metrics to heavily influence inbox placement. ISPs look at positive and negative engagement when determining if an email message or a domain’s email messages are going to reach their recipients’ inboxes. ISPs may not care about clicks (or even opens – we know how inaccurate that metric can be) in the email because they have access to lots of other data. Free inbox providers look at both subscriber-level engagement (how you engage) and global engagement (how ALL recipients engage) with your emails:

Positive engagement could include:

• Reply 

• Not junk 

• Move to folder 

• Add to address book 

Negative engagement could include:

• Move to junk 

• Delete without open 

• Ignoring the email; no opens, clicks, or any other positive engagement

Free inbox providers also look at IP reputation and authentication (SPF, DKIM, DMARC), but engagement may be weighed just as heavily. These days, having a decent IP reputation and maintaining your authentication protocol may not be enough to get your emails to their intended recipients.

Non-engagement filters also include signals such as “does this mail look unsolicited?” For example, if an organization is buying, harvesting, stealing, or otherwise acquiring lists in a non-permissioned way, then they will have high bounces, send mail to users who no longer (or never) existed, or generate complaints. Mailing old email addresses can send signals to ISPs that make mail look unsolicited.

2. Enterprise Outlook, Office 365, Outlook.com

Outlook administrators do not usually take into account subscriber-level or global engagement when determining inbox placement. IP reputation and authentication (SPF, DKIM, DMARC), as well as the users taking action to identify the email as spam are the primary signals that determine whether emails reach the inbox. Filters can be further customized, but each organization is going to approach it differently. With email hosting moving from on-premise to cloud hosting, filtering will eventually be handled completely by 3rd party applications such as Barracuda and Spamassassin. 

3. Google Workspace (Gmail for businesses)

Google Workspace has the potential to operate like Gmail, but with the option for administrators to customize filters. When Google Workspace is configured like gmail, engagement filters apply to all incoming mail. If they so choose, administrators can also add a layer of additional custom filters, and the larger the company, the more likely this is the case.

So, what does this mean for senders?

Consider how your marketing database is divided. How many free email addresses do you have? What about business addresses? Keep in mind that business mail filtering can differ from consumer mail. 

Remember that even if Outlook inboxes do not take engagement into account as much as free inboxes and Google Workspace inboxes, my recommendation is to apply best practices to email marketing that encourage engagement and permission-based marketing. I’ve seen 3rd party email security tools block purely based on IP addresses. I’ve also seen corporate recipients block all mail from sender domains presumably because their IT team received one too many complaints. This type of blocking is really difficult to overcome, and that’s why it’s important to practice safe email sending habits from the start. 

Always monitor and maintain your authentication records, monitor bounce rates and other factors that could negatively affect your email reputation, as well as maintain bounce rates within the accepted range. And while sending cold email is tempting, it’s considered spam whether you think so or not, so practice permission-based emailing whenever possible.