For help on this, refer to this article: Access another person's mailbox. There are a few different ways you can access a mailbox once you've been given access. How to use it once permissions are set up: Once you've set up the permissions, it can take up to 60 minutes for the changes to propagate through the system and be in effect. Refer to the following articles on how to set up each type of permissions: You can allow a user to read emails from the mailbox, send emails on behalf of another user, and send emails as if they were sent from that mailbox. This only happens in our App Layering image for Windows. Ive had both users run Outlook with no add-ins enabled and it still crashes. The first step to setting up permissions is deciding which actions you want to allow the other user to take in the given mailbox. Occasionally, when somebody is writing an e-mail (no attachments) and they click on Send, Outlook 2016 completely crashes: The crash log is less than useless, because it doesnt point to anything in particular.

The articles below might give you the help you need to set up and use this feature: Mailbox permissions allow you to give read/write access to a mailbox to another user. With Business Assist, you and your employees get around-the-clock access to small business specialists as you grow your business, from onboarding to everyday use. If you need help with the steps in this topic, consider working with a Microsoft small business specialist.

Outlook 2016 send as another user