MailEnable Enterprise Guide
Increasing 10000kb upload limit for Webmail
Appendix > Increasing 10000kb upload limit for Webmail

Uploading attachments larger than 10000KB fails through web mail.
HTTP runtime size limit restriction within the web.config file.
Navigate to the following location in the MailEnable .NET folder:
C:\Program Files\MailEnable\BIN\NETwebmail\
Locate the file "web.config" and open it up in Notepad. Locate the following line in the file:
<httpRuntime maxRequestLength="10240" executionTimeout="3600" />
The value that needs to be changed is: httpRuntime maxRequestLength="10240". Change the value to a size bigger to the file that is failing the uploading in web mail.

If changing the value within the MailEnable "web.config" file does not resolve the uploading failure, then the next step would be to inspect the following Microsoft Knowledge Base article that explains various situations and hardware limits that can impact on .ASPX uploading.;en-us;323245