Quick Fix: Set Default Max Send Receive Size in Exchange Online

Just because I’ll forget the right number of bytes to use. To set the Max Send/Receive size of a mailbox in Exchange Online PowerShell you should use 157,286,400 (bytes).

Set-Mailbox -maxSendSize 157286400 -maxReceiveSize 157286400

To set this as the default for new mailboxes for all mailbox plans:

Get-MailboxPlan | Set-MailboxPlan -maxSendSize 157286400 -maxReceiveSize 157286400

Then to confirm it worked:

Get-Mailbox | select MaxSendSize, MaxReceiveSize
Get-MailboxPlan | select MaxSendSize,MaxReceiveSize