I know this is a 2013 forum but my issue is with 2010. I adjusted the web.config file on the CAS but no matter how high I make the numbers, the limit seems to be around 22MB or so for attachments. I realize there is overhead with an email of up to 3MB or so and it's probably looking at the entire message, not just the attachment.
Has anyone with 2010 SP3 been able to accommodate attachments larger than 23-25MB? My Global and Receive Connector limits are fine. Issue is only with ActiveSync.