Exchange Online
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1h 10m

This Planning Office 365 Workloads and Applications course will teach you how to plan for Office 365 workload deployments and hybrid solutions. You will learn how to identify hybrid requirements for Exchange and SharePoint hybrid solutions, and how to plan connectivity and data flow for Office 365 services, including Exchange Online, SharePoint Online, and Teams. You’ll learn how to plan migration strategies for Exchange, SharePoint, and Teams, and how to determine the best strategies.

Later in the course, you will learn how to plan Office 365 application deployments and how to plan application updates. You’ll also learn about the different update channels and when to use each.

Learning Objectives

  • How to plan for Office 365 workload deployments
  • How to plan for migrations and hybrid solutions
  • How to plan for Office 365 application deployments

Intended Audience

  • IT professionals who are interested in obtaining an Microsoft 365 certification
  • Those tasked with planning Office 365 deployments and migrations


  • A decent understanding of Office 365 workloads, including Exchange Online, SharePoint Online, and Teams

When planning for Exchange Online, you need to estimate the Exchange Online network bandwidth that your organization is going to need. To do this, you'll need to make some assumptions about your user base. For example, you'll need to make a determination of what the average email size is that your users send and receive. A common estimate for this metric is 50 kilobytes. You'll also need to make some assumptions regarding the number of messages that are actually read. For this assumption, organizations will typically assume every message is read. At the same time, you should think about how much mail is deleted on a regular basis. Using a ratio of 50% isn't uncommon. You'll also want to estimate how many OWA users there are, and how often those users log on and log off of OWA every day. 

As you can see, there is actually quite a bit that goes into bandwidth estimation for Exchange Online. The table that you see on your screen shows what typical estimates would look like when planning for Exchange Online bandwidth. It breaks things out by light, medium, heavy, and very heavy email users. It is this type of information that you need to gather when planning bandwidth. 

This table here shows an estimated amount of network traffic that each type of email user generates. To use this information in your bandwidth planning, consider the following example: Assume that your organization employs 50 heavy Outlook users. To calculate the average network traffic that they generate, use the formula that you see on your screen. Essentially, this formula is network bytes per second equals the number of users times the bandwidth usage divided by 28.8k. 28.8k is the number of seconds in an eight hour day. Bandwidth usage refers to the bandwidth used by the type of user you're estimating for. Number of users is the number of users that you're planning for. Using this formula, we can determine that 50 heavy users will require nine kilobytes per second because 50 heavy users times 5,200 kilobytes per user, per day times 28,800 seconds per day equals 9.027 kilobytes per second. 

Now, if you assume daily peak activity of twice that, you should really be budgeting for 18 kilobytes per second for 50 heavy Outlook users. 

Phew, that's quite a bit of math, but, it's necessary when trying to determine the necessary bandwidth before deploying Exchange Online.

About the Author
Learning Paths

Tom is a 25+ year veteran of the IT industry, having worked in environments as large as 40k seats and as small as 50 seats. Throughout the course of a long an interesting career, he has built an in-depth skillset that spans numerous IT disciplines. Tom has designed and architected small, large, and global IT solutions.

In addition to the Cloud Platform and Infrastructure MCSE certification, Tom also carries several other Microsoft certifications. His ability to see things from a strategic perspective allows Tom to architect solutions that closely align with business needs.

In his spare time, Tom enjoys camping, fishing, and playing poker.