I recently upgraded from SBS 2003 to SBS 2011. Pretty much all is well. Running Exchange 2010 SP1 (plan on upgrading to SP2 this weekend). However, external e-mails with larger r attachments somewhere around 7MB and up don't get delivered to mailboxes on our Exchange server. 24 to 48 hours later the sender gets a non-delivery report with either an smtp timeout or smtp read error listed. Our incoming e-mail is filtered via Postini, but never had trouble like this before. I think I have all of the limit size options disabled in Exchange 2010. Any suggestions?