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Exchange database size recommendations

You need to know the Exchange database size limit and recommendations for running an optimal Exchange Server 2016/2019 environment. The Exchange database recommended size is important to know. For example, you want to consult or architect a new configuration to the existing Exchange environment. In this article, you will learn the Exchange database size best practice.

Exchange database size recommendations 2016/2019

The Exchange database size recommendations are as follow:

  • Exchange High Availability (replicated) a maximum of 2000 GB (2 TB) per database
  • Exchange Standalone (non-replicated) a maximum of 200 GB per database

By replicated, we mean a Database Availability Group (DAG).

It’s about recovery time. The restore of a database will take longer if the size of a database is big. A smaller database in size will be faster to restore. For example, you have a 100 GB database and a 1000 GB database in size. Both of them did fail, and you need to restore both databases from your backup. Which database is faster to restore and put back online? The answer: the Exchange database that is smaller in size.

Exchange database size limit 2016/2019

Exchange Server comes in two editions:

  1. Standard Edition
  2. Enterprise Edition

Read more: Exchange Server Edition comparison »

Exchange Server Standard Edition

  • Maximum of 5 mounted databases per server
  • Database size limit is 1 TB (1024 GB)

Exchange Server Enterprise Edition

  • Maximum of 100 mounted databases per server
  • Database size limit is 16 TB (16384 GB)

Keep reading: Exchange database best practices »


To sum it up, you did learn the Exchange database size recommendations. Keep the databases smaller than 200 GB on a standalone Exchange Server and 2000 GB if it’s a DAG configured Exchange Server. Always keep the Exchange database size limit in mind. Now that you know the Exchange database size best practice, will you be changing your Exchange environment?

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ALI TAJRAN is a passionate IT Architect, IT Consultant, and Microsoft Certified Trainer. He started Information Technology at a very young age, and his goal is to teach and inspire others. Read more »

This Post Has 3 Comments

  1. Hi,
    it’s possible to manage one lakh/100k mailbox with Exchange 2019 Enterprise edition, if possible, please suggest hardware specifications like processor, RAM.


  2. Hi,
    Thanks for the post, i have one question:
    What is the maximum number of mailboxes per database?
    It is possible to limit the number of mailboxes per database?

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