We set up a new incoming email list on our SharePoint 2010 site and allowed it to receive attachments. We tested the email worked correctly and the list could receive the emails with attachments. However, when end users attempted to email a large attachment, they received the following message:
"This message exceeds the maximum message size allowed. Microsoft Exchange will not try to redeliver this message for you. Please make the message smaller -- by removing attachments, for example -- and try sending it again, or provide the following diagnostic text to your system administrator."
The Web application was set to allow for 1024 MB for uploads which was plenty large enough for our use. Also, the list settings were set correctly to allow attachments.
The issue turned out to be the settings on the SMTP side. To fix it, go to IIS 6.0:
- Expand the server name and right-click on SMTP Virtual Server.
- Select the Messages tab
- Adjust the settings according to your allowable limits