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Migrating mailboxes from on-premises Exchange or Exchange Online to Exchange Online or Microsoft 365 tenant server requires ample resources and time. Mailbox migration in the Exchange environment makes it easy for users to access email from anywhere around the world. It is, therefore, essential to find ways that can improve the performance as large mailbox migrations are slow because of network latency.
Before we learn how to improve the performance, let us check out different methods to perform mailbox migration in Exchange Server.
Exchange Server provides a messaging platform where you can communicate with others by sending emails, creating tasks and calendars, sharing attachments, and even more with the email client Outlook. Here are the five types of migration methods mentioned that you can proceed with to migrate your mailbox database:
Exchange Server migration can get slower when you try moving large mailboxes due to network latency. Factors that cause this include hardware (such as CPU and storage), load on the Exchange Server, internet connectivity, firewall restrictions, and a higher value of the SourceSideDuration (when it goes beyond the expected range of 60 to 80 percent). If you want to know how to resolve the issue of ‘large mailbox migrations are slow because of network latency,’ below are some preventive measures to follow.
Ask your network support engineer to provide good internet connectivity and filtering when you are migrating mailboxes of large sizes. The upload should be high enough to provide a reasonable throughput.
For Exchange Server 2013 with Service Pack 1 and subsequent editions, you can raise the export buffer size. Add the ‘ExportBufferSizeOverrideKB’ to the MRSConfiguration section of the ‘MSExchangeMailboxReplication.exe.config’ file.
It will diminish the migration calls and the time spent in network latency. The suggested maximum and minimum values for this setting are 7,500 and 512, respectively. However, if you change the value of the ‘ExportBufferSizeOverrideKB’ parameter, change the ‘DataImportTimeout’ value too.
Set the ‘DataImportTimeout’ value in the ‘MRSProxyConfiguration’ of the ‘MSExchangeMailboxReplication.exe.config’ file to correspond to the minimum upload rate that you can sustain during the migration.
Do not go lower than this rate. You can increase the ‘DataImportTimeout’ value a bit more than the total minimum.
If you plan to migrate the user mailboxes with a hassle-free migration experience, go with third-party software or tools. One such tool to do this is Kernel Migration for Exchange. It helps in migrating user mailboxes safely from on-premises Exchange, or Office 365 to Exchange Online, PST files, or to other Office 365 tenants.
While migrating or converting your EDB files, you get to them in EML, MSG, RTF, HTML, or TXT formats. It is a great alternative to migrating mailboxes of all sizes, and the best part is that there are no slow performance issues when migrating with Kernel for EDB to PST converter tool.
The strategies stated in this article allow you to perform migration efficiently. If the issue, ‘large mailbox migrations are slow because of network latency,’ is still there, employ Kernel Migration for Exchange.
This tool will make the mailbox migration job extremely easy for you. You can even export your mailbox database by converting it into a variety of file formats, including PST, MSG, and MBOX. Our tool also allows you to open files from any on-premises Exchange version, even if you don’t have a working server.