Setting such a high limit opens you to other problems, however. E-mail is not meant to handle such large attachments. An attachment of this size should be placed on an FTP site for the recipient to download. It could be your site or the recipient’s site. With the mailbox size limits imposed by some companies, one or two messages with attachments of this size would effectively shut down the user’s mailbox for, at least. sending mail. Also think of the effect if the recipient’s mailserver does not allow mail of that size to be received. You get the bounce, with a 27+ MB attachment.

Another factor to consider is that if you do it for one user, you’ll get another user who wants an increased limit, and eventually you will have a snowball effect on your mail infrastructure.

One of my clients has a very generous limit of 15 MB for attachments, mainly for the editorial department who deal with large graphic files. Anything above that limit is to be placed on the FTP server maintained for that purpose only. High quality photo files can easily exceed 30 MB. This has worked very well for them (except when they forget the instructions to give the sender to access the server).

You can set your server limits (ESM => Global => Message Delivery properties)default value for sending message size to no limit then use ADUC properties to restrict message size on a per user basis to solve your problem.

One thing you should not overlook is any SMTP firewall policy settings that you have in place. Make sure your firewall policy has a value equal or greater than your server or users ADUC properties are set or this will become your point of failure.

Good luck!