Have your users ever complained about not being able to send email that had large attachments?

Sometimes your end users will try to send emails that contain large files that are maybe ten (10) to twenty (20) megabytes or larger. After they hit the submit button they’ll get an error message that goes something like: “The message being sent exceeds the message size established for this user.” You can check the user’s outbox and the message is still there.

This can happen with Exchange using Outlook. Outlook may or may not be setup in Exchange server cached mode. One thing you can do is to have the Exchange system administrator check the global send size limits. Then compare those limits to the size of the outbound email attachment. If the email attachment exceeds that size limit then you can have your user try zipping the file(s) so as to reduce the total size of the attachment(s). Then try re-sending the email.

The user may also have to consider splitting the attachment into smaller pieces and then resend those smaller chunks in separate emails. Sometimes users are sending PowerPoint attachments which can be very large when graphics and images especially are added to the presentation. The user could break the presentation into a sequence of three or four sections and then resend those sections separately.

Every once in a while you have the situation where you’ve attempted to preempt a potential problem by cleaning up a folder such as the Sent Items folder. One admin had reported that they removed a large message from the Sent Items folder after they surmised that the large message was not going to get past the recipient’s firewall and that the message was too large. After doing so they then started getting the 0×80040610 error code. They then tried to cancel all (pending transactions) but received another error indicating that the task was cancelled before it was completed.

It turned out that the cancelled email was still stuck in the Microsoft Exchange Server because it had exceeded the file size limit – as discussed previously. Deleting the file resolved the issue and stopped the error message from being generated.

A possible solution would have been to add a new profile through the mail icon in the control panel. Once successful then you could move the mail from the old profile into the new one.

You can also check your email settings. It’s possible that you might have the following parameter settings and still need to make some changes.

get-sendconnector showing all send connectors have a maxmessagesize of 150MB

get-receiveconnector showing all receive connectors have a maxmessagesize of 150MB

get-transportconfig showing a MaxSendSize to be unlimited

get-Mailbox also shows MaxSendSize is unlimited

If this is the case you may still be able to receive large emails.

You can restart the Microsoft exchange transport service and server to make your setting changes permanent. You can also try setting the TransportConfig to unlimited and Mailbox limits to a fixed value.

Make changes to TransportConfig and Mailbox limits by going to the Exchange Management Console (the GUI tool). From there, go to the Recipient Configuration area and then to the Mailboxes. Select a user and then edit their properties. Select the “Mail Flow Settings” tab.  Highlight the “Message Size Restrictions” and click the properties button.  If you see the that Sending Message Size and Receiving Message Size “Maximum Message Size in KB” are unchecked, then this can result in  an “unlimited” value for the get-Mailbox report of MaxMessageSize. 

You can also set your own value by checking both boxes and entering a value such as 102400 (100 MB in KB). Then save your new settings.  You should now be able to send large files larger up to 100 megabytes in size.  Change your remaining user values as appropriate. You should now be able to see a value of 100MB for the get-Mailbox parameter in the Exchange Management Shell for all mailboxes that have been changed using that value.

Note that you can change the values for all users or you can set the TransportConfig value and it will apply to all users. For example,

Set-TransportConfig -MaxReceiveSize 100MB -MaxSendSize 100MB

Another reported workaround is to stop the Edge Synchronization:  configure the hub transporter to allow the desired size limits and then restart the Edge Sync with the updated hub transporter configuration.