In many situations, it’s useful to grant others access to part or all of your mailbox. Given how many options are available to accomplish this, ask yourself these questions to determine which method is best:

1. What kind of access does the other person need?
   
   • Viewing your Calendar
   • Viewing some or all of your email
   • Move or delete items, accept appointments, or even send mail on your behalf
2. What part of your mailbox needs to be accessed?
   
   • Just your Calendar
   • Certain mailbox folders (e.g. Inbox or Sent Items)
   • Your entire mailbox
3. Who needs to have this access?
   
   • One person
   • A group of people

Also, consider how security concerns impact your decision. You should grant minimal access to as few people as possible to accomplish the task at hand. It may be helpful to review the various permissions/delegation options described in the Sharing Permissions Glossary at the bottom of the page at this link.

In Office 365, you can:

Share your calendar

• This is the recommended option for someone who needs only to view your calendar.

Sharing mailbox folders

• This is the recommended option if someone needs to access some of your mail (e.g. one or two folders containing information about an ongoing project).

Note: it is not recommended to share your entire mailbox. If you need to grant this level of access to someone, adding them as a delegate is the best option.

Grant a person access to your entire account by making them a delegate

• This is the recommended option if you would like to allow someone to accept calendar appointments, move/view/delete mail, or send email from your account on your behalf.