Hi thanks for the suggestions regarding the rules.  I think I am ok just putting a 10mb limit on mercury as this has all come up because the bounce back for large mail wasnt working when it was set to zero.

Thanks Graham

Hi we have mercury as a SMTP gateway server between our router and our exchange server.  I had mercury setup with no ESMTP maximum message size limit so it was passing big emails over 10mb to exchange 10mb being the limit on our exchange server.  When mercury tried to deliver say a 25mb email to exchange I saw a failure in the ESMTP log but the sender gets no bounceback so they just seem to black hole.  Is there a way to get mercury to send bounceback when the S SMTP server has recieved the mail ok but the E SMTP server cannot deliver it to exchange?

At the minute I have set Mercury S SMTP server to reject all mail over 10mb to stop this happening but we might want to setup a mailbox on exchange for large mail and if I do that I will have to get rid of the limit on mercury.

Thanks Graham

It might be possible to accomplish with you need with outgoing mail filters.  In envision one that checks message size and then sends a response to the sender followed by a deletion of the message.  I don't know whether the response to sender would or could specifically identify the blocked message.

We use this. I have a rule configured that blocks messages more than 20MB in size. The sender receives a notification that their message has not been delivered, what the maximum size is and a copy of the entire message is delivered to the postmaster account. The last bit is not really required but it allows me to keep tabs on repeat offenders and follow up with training if needed.