Big Green IT supports a number of ways to access mailboxes.  If you do not have administrative access to the mailbox, there are several ways you can access the contents:

Gather mailbox passwords:

This is simple. You can gather passwords from users. In most cases this approach is not practical nor very secure, and therefore we do not recommend it.

Reset mailbox passwords:

You can always reset the passwords to mailboxes to something that you know and control. The problem with this method is that your end user is locked out of his/her mailbox as their password has changed. You may optionally give them the password you have set but end users are prone to changing the passwords to something they can remember, which may cause your migration to fail mid-way. If you do not plan on giving the end users the passwords, this may be a viable options if you do not mind locking them out of the mailbox.

Request mailbox passwords from each mailbox:

Big Green IT offers a unique feature which allows the system to request the user name and passwords directly from each end user.  This gives you the ability to access the mailbox while the end user is using it. Learn more about the request credentials process.