Sometimes, the default maximum message size (including attachments) in Exchange is not enough (30 MB is the standard). To increase this to 100 MB, do the following: Open the Exchange Management Shell as Administrator. First check the current maximum size on all relevant Exchange components: Get-TransportConfig | ft MaxSendSize, MaxReceiveSize Get-ReceiveConnector | ft Name, MaxmessageSize Get-SendConnector | ft Name, MaxMessageSize Get-Mailbox Administrator |ft Name, MaxsendSize, MaxReceiveSize Then Read more [...]