Send as distribution group Exchange 2007/2010

To enable sending as a distribution group in Exchange 2007 / Exchange 2010

EMS:
Add-ADPermission -Identity "group name" -User "user alias" -AccessRights extendedright -ExtendedRights Send-As

Outlook:
To test straight away, Download the offline address book (click Send/Receive tab, click Send/Receive groups and select Download Address Book).
Send test email from distribution list.

Could not deliver the message in the time limit specified. 4.4.7 MaxHeaderSize

Increase MaxHeaderSize on Exchange 2007 and Exchange 2010

Emails with large headers/many recipients bounce to external senders with 4.4.7 Could not deliver the message in the time limit specified.

To check current configuration:
Get-ReceiveConnector | ft name, MaxHeaderSize

To set a new limit:
Set-ReceiveConnector “Windows SBS Internet Receive Servername” –MaxHeaderSize 128KB

Source – Exchange Inbox
Source – Technet

Increase email size limits in SBS 2008/2011

To increase the send and receive limit for all users on Exchange there are 3 settings that need adjusting. Global Transport, Receive Connector, Send Connector.


Global Transport Settings

To check current configuration:
Get-TransportConfig | ft MaxSendSize, MaxReceiveSize

To set a new limit:
Set-TransportConfig –MaxSendSize 30MB –MaxReceiveSize 30MB


Receive Connector Settings

To check current configuration:
Get-ReceiveConnector | ft name, MaxMessageSize

To set a new limit:
Set-ReceiveConnector “Windows SBS Internet Receive Servername” –MaxMessageSize 30MB


Send Connector Settings

To check current configuration:
Get-SendConnector | ft name, MaxMessageSize

To set a new limit:
Set-SendConnector “Windows SBS Internet Send Servername” –MaxMessageSize 30MB

Source: Official SBS Blog