Can we say that very big messages should not be retrieved (downloaded)? How would the user know about the message in such conditions?
You may specify a size limit for incoming messages. Along with this, you may also specify if a big message must be kept in the Internet server or deleted from there. In either of these cases, the message headers are retrieved, and sent to the user (local recipient), indicating that the beyond limit message is deleted or kept as the case may be.