First of all Most of the Outlook users are facing this issue and asking for the solution. It is an issue that occurred while sending emails.
So how to solve this [pii_email_84eb7572bd91baae7e9f] error code? Just follow these simple steps and your issue will be resolved in minutes.
[pii_email_84eb7572bd91baae7e9f] Error Code Resolved
Why this Error occur?, this [pii_email_84eb7572bd91baae7e9f] error code appears when you have an older version of Outlook.
If this is the problem, you have tried to upgrade it to the latest version. And you must download latest from official Microsoft Outlook website.
And another one is, if you outlook conflicts with any of software applications in your computer. So, you have to figure out that Outlook is conflict with any other software and try to remove it.