NOTE: This article is ONLY applicable for Exchange 2019, 2016, 2013, 2010 & 2007

Email often carries more than just a message. It can also other types of data embedded within the body or as an attachment to the email. To protect mailbox databases from uncontrolled growth due to massive use of mail attachments, Microsoft Exchange incorporates a special set of message size limits in its configuration.


Problem Overview

During a restoration with DigiScope's Exchange EDB recovery tool you receive the error "Message being sent exceeds the message size established.....".  As the error suggest the message could not be restored because the item(s) in question exceed the current set limits.  This usually happens when a new server is setup and the defaults are not changed to match the corporate policies OR if historical data being restored exceeds the current policy in place.  Please review and keep in mind the following when attempting to restore an Exchange mailbox with DigiScope:

  •  MESSAGE SIZE
    • The size of a message includes the entire content of the message, i.e. not only any attachments but also the information within all fields of the message as well, i.e. if you have embedded objects directly within the email such as showing pictures. spreadsheet cells etc., that information along with any attachments make up the actual size.
    • As a message routes from mail system to mail system it can get larger than when it started. This happens because as a message traverses different mail systems, transcoding (or Base64/MIME conversion) may occur. On average this results in a 33 percent larger message than when it left your outbox. Therefore take this into consideration and consider increasing the setting by 33%. For example if I want to ensure that a 50MB message can get through if transcoding occurs I would want to set my limit to 67MB.


  • AFTER MAKING ADJUSTMENTS

    • Once you make changes for message size, even though the changes appear to be updated it may take up to 2hrs or more for changes to actually take effect

    • To make changes take effect immediately: Restart the Microsoft Exchange Information Store & Microsoft Exchange Transport service.


NOTE: Be aware that restarting the Information Store service will dismount and remount all exchange databases on the server which will interrupt mail flow temporarily.



Problem Resolution Overview

DigiScope displays information onscreen about any items it cannot restore and also logs information about the message location, title and reason each item cannot be restored.  This information is located within the DigiScope/Logs/Restore folder. For each Exchange mailbox restore job there will be a "Date/time - NotRestored" folder and within each folder there will be a separate CSV file for any mailbox where items were not restored. Depending on your situation you have two options for resolution as outlined below.


NOTE: When using the default settings DigiScope will not restore duplicates of an item, therefore if you decide to stop and restart the restoration process it will not duplicate items previously restored.


LET THE RESTORE FINISH AND THEN TAKE ACTION  

Should you be well into the restoration process and only have a few incidents of messages not being restored you may want to let the current restore finish and then once completed do the following;

  1. Close DigiScope
  2. Review the CSV files for each mailbox which as stated above will be located within the DigiScope/Logs/Restore folder
  3. Check & Modify the limits to allow for restoration of items exceeding the message size limits
  4. Open DigiScope
  5. Use the appropriate CSV file to identify items within a mailbox that failed to restore because of size limits and restore each item via Drag-N-Drop or the Restore Wizard 


STOP, ADJUST AND RESTART THE RESTORE 

If  you just started your restore and are getting the error regarding message size restrictions OR your getting a large # of errors its probably wise to stop the restoration, adjust the settings and then restart the restoration.  Restarting could be much more efficient since manually reviewing and restoring a large # of items that didn't restore could take substantial effort. 

  1. Stop the DigiScope restoration
  2. Disconnect DigiScope from the Production Databases
  3. Check & Modify the limits to allow for restoration of items exceeding the message size limits
  4. Connect DigiScope to the Production Databases containing the mailboxes for restoration
  5. Restart the restoration



Areas Restricting Message Size Limits

There are three areas you can configure message size limits with Exchange

  • User mailbox settings
  • Send/Receive connector settings
  • Organization transport settings


CHECKING CURRENT MESSAGE SIZE RESTRICTION SETTINGS

Before you can make adjustments its necessary to determine the current settings by following the steps outlined below


1. Open the Exchange Management Shell.

2. Replace the “{user or display name of mailbox}” within last line of code below with the User or Mailbox name that's experiencing the "Message being sent exceeds" error. 

3. For example, if I was having issues restoring messages with a 15MB attachment to the user/mailbox named "Pilar Ackerman"
 that last line would read as  get-mailbox “Pilar Ackerman” |ft Name, MaxSendSize, MaxReceiveSize 

4. Adjust and then highlight the updated code with your affected user name input and then CTRL+C to COPY the code to the clipboard


----------------  MODIFY & THEN COPY CODE BELOW INTO EMS  -----------------------------


get-transportconfig | ft MaxSendSize, MaxReceiveSize
get-receiveconnector | ft name, MaxMessageSize
get-sendconnector | ft name, MaxMessageSize
get-mailbox “{user or display name of mailbox}” |ft Name, MaxSendSize, MaxReceiveSize



4. Left click on the upper left corner of EMS or remote PowerShell and select Edit/Paste to paste the code into the console.  

5. Hit Enter 1 time.


6. The code executes and you will see results similar to the once shown below.

NOTE: If you receive errors after pasting the code in place, review the error messages, make adjustments as needed and re-paste/execute the code




7. As you can see within the above example if Pilar has messages with a 15MB attachment or larger there are 3 areas with lower then 15MB thresholds.


8. Before making any modifications write down the current settings so that you can put them back or modify them to meet your organization policies post restoration completion. 



MODIFY MESSAGE SIZE RESTRICTION SETTINGS

Now that we know the current settings we can use the code below to adjust the settings after replacing the placeholder parameters within the bolded curly brackets { }.


----------------  MODIFY & THEN COPY CODE BELOW INTO EMS SEE EXAMPLE BELOW -----------------------------

Get-MailBox “{user or display name of mailbox}” |Set-MailBox –MaxReceiveSize {size in KB, MB, or unlimited} –MaxSendSize {size in KB, MB, or unlimited}
Set-TransportConfig -MaxReceiveSize {size in KB, MB, GB, or Unlimited} –MaxSendSize {size in KB, MB, GB, or Unlimited}
Get-SendConnector | Set-SendConnector –MaxMessageSize {size in KB, MB, GB, or Unlimited}
Get-ReceiveConnector | Set-ReceiveConnector –MaxMessageSize {size in KB or MB. Min size is 2KB, maximum size is 2047MB}


For example using our test scenario with Pilar: 


1. While the TransportConfig settings were set to Unlimited, you will see in the example below that we changed all four settings within the code to use 50MB.  We did this so that you have an example of how to adjust each of the settings. 


2. After making the desired changes we highlighted the code and used CTRL+C to COPY the code to the clipboard 


Get-MailBox “Pilar Ackerman” |Set-MailBox  –MaxReceiveSize 50MB –MaxSendSize 50MB
Set-TransportConfig -MaxReceiveSize 50MB –MaxSendSize 50MB
Get-SendConnector | Set-SendConnector –MaxMessageSize 50MB
Get-ReceiveConnector | Set-ReceiveConnector –MaxMessageSize 50MB


3. Left click on the upper left corner of EMS or remote PowerShell and select Edit/Paste to paste the code into the console.  

4. Hit Enter 1 time and if the settings are proper you will see something similar to the output below, confirming that the desired changes took place.


5. Double check to ensure all is well by following the "CHECKING CURRENT MESSAGE SIZE RESTRICTION SETTINGS" section of this document above

 

ADJUSTING SETTINGS FOR ALL MAILBOXES WITHIN A DATABASE


If you find that all users within a database need to be updated you can accomplish this by replacing the database name with the placeholder in curly brackets {} and then pasting the code  into the Exchange Management Console


CHECKING MAX SEND & RECEIVE SIZE FOR ALL MAILBOXES WITHIN A DATABASE

  • CODE TEMPLATE: Get-MailBox –Database “{database name}” | fl DisplayName, MaxReceiveSize, MaxSendSize
  • UPDATED EXAMPLE FOR SPECIFIC DATABASE: Get-MailBox –Database “Lucid8 Exchange 2016 Demo Database” | fl DisplayName, MaxReceiveSize, MaxSendSize




ADJUSTING MAX SEND & RECEIVE SIZE FOR ALL MAILBOXES WITHIN A DATABASE

  • CODE TEMPLATE: Get-MailBox -Database “{database name}” | Set-MailBox  –MaxReceiveSize 50MB –MaxSendSize 50MB
  • UPDATED EXAMPLE FOR SPECIFIC DATABASE: Get-MailBox -Database “Lucid8 Exchange 2016 Demo Database” | Set-MailBox  –MaxReceiveSize 50MB –MaxSendSize 50MB


AFTER MAKING ADJUSTMENTS

  • Once you make changes for message size, even though the changes appear to be updated it may take up to 2hrs or more for changes to actually take effect

  • To make changes take effect immediately: Restart the Microsoft Exchange Information Store & Microsoft Exchange Transport service.


NOTE: Be aware that restarting the Information Store service will dismount and remount all exchange databases on the server which will interrupt mail flow temporarily.


SUPPORT: If you experience issues, have questions or need assistance after following these instructions please Open a New Support Ticket or if you already have a ticket open reply with details and we will be happy to assist.  That said, Lucid8 is providing the information herein as a courtesy. This article is not intended to be nor imply a service contract to resolve Microsoft related issues and providing you with this information does not commit Lucid8 to support or assist with any Microsoft related features, capabilities or responsibilities. To say it another way, this article is here to help resolve the message size issue as quickly as possible.  However if your Exchange environment does not respond to the adjusted settings or if you have other Exchange related issues we are not obligated to assists unless you engage Lucid8 under a "Paid Professional Services Agreement".