There are a number of features in mojoPortal which allow for uploading files, however the maximum file size that can be uploaded depends upon configuration.
Overview
When running in Full Trust, mojoPortal uses NeatUpload and the file size limits are controlled by the NeatUpload section in Web.config.
<neatUpload xmlns="http://www.brettle.com/neatupload/config/2008"
useHttpModule="true"
maxNormalRequestLength="4096"
maxRequestLength="2097151"
multiRequestUploadHandlerUrl="~/NeatUpload/MultiRequestUploadHandler.ashx"
maxUploadRate="300"
></neatUpload>
Whereas, when running in Medium Trust NeatUpload is disabled and file upload limits are controlled by the httpRuntime settings like this:
<httpRuntime maxRequestLength="2097151" executionTimeout="3600" useFullyQualifiedRedirectUrl="true" />
IIS 7
If you use IIS7 you also have to do the following (see discussion at http://forums.iis.net/p/1108662/1702390.aspx):
at an elevated (run as admin) command prompt enter:
%windir%\system32\inetsrv\appcmd set config "MySite/MyApp" -section:requestFiltering -requestLimits.maxAllowedContentLength:104857600 -commitpath:apphost
you can verify that the setting was inserted OK by doing and checking out the output:
%windir%\system32\inetsrv\appcmd list config "MySite/MyApp" -section:requestFiltering
the command is changing the maxAllowedContentLength request limit that IIS7 requestFiltering (the replacement for urlscan) has introduced
NeatUpload documentation also mentions the following alternative regarding the IIS7 issue:
(Optional) To allow larger uploads than the 30MB default used by IIS7, add the following to your Web.config under the configuration/system.webServer/security/requestFiltering section:
<requestLimits maxAllowedContentLength="size_in_bytes"></requestLimits>
Note that for such a change to be allowed, you or your hosting provider might need to change the machine's %SystemRoot%/system32/inetserv/config/applicationHost.config file such that the overrideModeDefault attribute for the requestFiltering section is Allow instead of Deny.
Additional Resources:
http://msdn.microsoft.com/en-us/library/aa479405.aspx
http://aspnetresources.com/articles/dark_side_of_file_uploads.aspx