I had a meeting last week with a non-profit and during our discussions I heard many of the same things that I have heard in the past which indicate a total lack of understanding on the part of the end-user organization as to how their Outlook and Exchange actually work.\u00a0 And it isn\u2019t just end-users that seem to be confused, I have seen IT pro\u2019s that also are completely in the dark, sadly more often than you would think.\u00a0 And then I realized that there is little point in discussing Office 365 migration strategies if there is no understanding of the basic mechanics of Outlook and Exchange.\u00a0 So, I\u2019m going to do my best to lay out the basics in this post so that you have the knowledge you need to help you evaluate your migration options.<\/p>\n
Stating the obvious, Exchange is the backend server that supports all of the functions of Outlook.\u00a0 Whether you are on-premise or in the Cloud (O365 or some other hosting provider), if you\u00a0 want Outlook to be fully lit up you need to be talking to Exchange.\u00a0 Exchange does many things; it is the email server, it is the backing store for all of your Outlook data, it hosts your Calendars and contacts, it is the \u201cengine\u201d that drives it all.\u00a0 And it does this by various channels as it supports Outlook, it provides online access via OWA (webmail), it supports connections from phones and tablets.\u00a0 It holds your \u201chistory\u201d \u2013 all of your received and sent email, contacts and calendar info \u2013 as well as a bit of your future in the sense that your calendar holds future appointments, tasks and reminders.\u00a0 And it is centralized so that all of the tools that access it \u2013 Outlook, OWA, the channels to drive phones and tablets \u2013 look at the same data.\u00a0 If you make a change\u00a0 in Outlook you can see the same change in OWA and on your devices.<\/p>\n
<\/p>\n
Exchange doesn\u2019t live in a vacuum, it always lives within an Active Directory which is the Microsoft backend for managing user information, security and authentication.\u00a0 Whether you realize it or not, if you have an Exchange account you also have an Active Directory account.\u00a0 Your AD account may be on-premise, it may be in the Cloud (as in Office 365 and\/or Azure) or it may even be in both<\/em> through a synchronization mechanism such as DirSync, AADsync or AADconnect which shares an synchronizes AD data between on-premise and Office 365\/Azure.\u00a0 You must have an AD account in order to have an Exchange account.\u00a0 There are many,many pieces of information that Active Directory can hold for a particular user and some organizations populate many more of those information fields than do others.\u00a0 Exchange makes use of some very specific fields that have to be populated in order for everything to work.\u00a0 You don\u2019t need to know about the fields for this discussion, just that they are there and they are referenced on a regular basis.<\/p>\n Outlook is the Microsoft application that surfaces all of the Exchange data that is held for you on your PC.\u00a0 I describe it this way as it is not the only<\/em> tool to get to the data as OWA, your phone and your tablet also do the same thing.\u00a0 There was a time, however, when Outlook was the only game in town.\u00a0 Outlook has always been built to run in one of two modes when talking to Exchange:\u00a0 Cached mode and non-cached.\u00a0 Non-cached mode makes Outlook operate simply as a presentation interface into Exchange.\u00a0 Any information that is being displayed is being directly relayed from Exchange itself, there is nothing \u201clocal\u201d to the PC.\u00a0 Outlook in non-cached mode is rather like using OWA without using a browser.\u00a0 Cached mode creates a local copy of your Exchange data which Outlook then references first<\/em> before requesting updated information form Exchange.\u00a0 The idea is that network traffic is reduced and your information is available to you even if you have no network connection.\u00a0 In the majority of cases, users run Outlook in cached mode as it is the default configuration.<\/p>\n If you are talking to Exchange in cached mode then you will have a local OST or PST file (depends on your version of Outlook) which is the local cache file for your Exchange data. These files are tied to a specific Outlook profile on your machine.\u00a0 Each specific Outlook profile will have its own set of associated files. PST files are the older file type while OST files came into play with Outlook 2007 and newer.\u00a0 OST files can be much larger than PST files which have an upper size limit of 2GB.\u00a0 PST files, on the other hand, are truly standalone copies of your data and they can be used for more functions than just caching your Exchange data.\u00a0 The archiving function in Outlook uses PST files to hold your archive data locally on the PC (it is not held inside Exchange).\u00a0 A PST file is the only<\/em> file type for holding a local copy of your data if you have created a link inside Outlook to a non-Exchange mail server such as Gmail or a POP3 mail server.\u00a0 And if you use the export function in Outlook one of the file types that you can create is a PST.\u00a0 PST files can be used to transfer data from one user to another or one machine to another.<\/p>\n <\/p>\n Every user that is being migrated to Office 365 will require two things:\u00a0 an Office 365 account (identity) and an Office 365 subscription (license).<\/p>\n OK, now that you have the basics we need to discuss how all of this ties together at migration time.\u00a0 But first we need to discuss the why\u2019s<\/em> of migration.<\/p>\n If you have a brand-new organization and brand-new Office 365 account\u2019s there probably is no need for migration as there is nothing to migrate.\u00a0 On the other hand, if you have had email running for years, Exchange or otherwise, you probably want to see the history and the forward data (think Calendars) imported (migrated) into Office 365.\u00a0 And that\u2019s where understanding the in\u2019s and outs of Outlook and Exchange really comes into play.<\/p>\n The size and scope of your organization\u2019s email \u201cfootprint\u201d has a lot to do with how you migrate into Office 365; migrating 5 users is considerably easier and less complex than migrating 500 or 5000.\u00a0 But the end goal is always the same and that is to ensure the data that is in the old system, whatever it might be, is replicated without error and with full \u201cfidelity\u201d into Office 365.\u00a0 After all, what is the point of having a system that allows you access from pretty much anywhere and from almost any device if your precious data isn\u2019t there?<\/p>\n Migrating only a few users can be accomplished fairly easily by just doing a PST export on the old system (old Outlook profile) and then import that data into Office 365 via the import function in Outlook.\u00a0 Pretty simple overall but it quickly becomes tedious if you have more than a few users involved.\u00a0 Also, a PST migration does not address issues around migration of shared data <\/em>from Exchange (address books, public folders, distribution groups, etc.) or from other centralized email systems.\u00a0 PST migrations can impose a significant load on your Internet connection if you have a number of users all trying to import their data at the same time so the best thing to do is to \u201cstage\u201d it a few users at a time.<\/p>\n I have worked with a few customers to do this type of migration and have seen it work successfully for up to about 20 users.<\/p>\n My next post will discuss Complex Migrations and the methods that can be followed to ensure success.<\/p>\n","protected":false},"excerpt":{"rendered":"<\/h1>\n
Outlook<\/h1>\n
OST & PST<\/h1>\n
<\/h1>\n
Office 365 Account<\/h1>\n
Simple Migration<\/h1>\n