DOCUMENT:Q118359 10-NOV-1999 [macmail] TITLE :Mac Srv: Mail Data Files Can Increase in Size Quickly PRODUCT :Microsoft Mail For Appletalk Networks PROD/VER:WINDOWS:3.0,3.1 OPER/SYS: KEYWORDS: ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Mail for AppleTalk Networks, versions 3.0, 3.1 ------------------------------------------------------------------------------- SUMMARY ======= In versions 3.0 and 3.1 of Microsoft Mail for ApleTalk Networks, the Mail Data file can grow large quickly in some known cases. Many of Mail's operations or algorithms use a lot of disk space, to be reclaimed during compression in the interest of making the Mail server faster. MORE INFORMATION ================ Sending an enclosure to a user on another server is expected to temporarily increase the destination server's data file by twice the size of the enclosure. This is because a server to server "wrapper" containing the enclosure and the message is sent across the network, which the destination server then must unpack into its parts: the enclosure and the message. The original wrapper is then "deleted," but its space in the data file may not be reclaimed until the server has been relatively idle for a while (for example, overnight). This unreclaimed space may actually be used by the server before the compression routines kick in. In some cases (for example, an active server with lots of free space in its data file), an incoming message or enclosure may actually not increase the size of the data file at all; free space within the data file (of the right size) can be used for the wrapper and its parts. Breaking up this wrapper is called "message delivery." This is where all recipients of the message get a copy in their mailboxes. Mail does not duplicate the message for each recipient, but puts a reference to the message in each recipient's mailbox. This means copying the mailbox, adding a reference to the message, and deleting the old mailbox. Each of these mailbox updates temporarily requires twice the size of the mailbox being updated since the mailbox is copied to a new place in the data file and the new message appended to the mailbox. For a message to many users with big mailboxes, this could easily increase, by a lot, the space temporarily required for message delivery. In addition, a completely compressed data file tends to increase in size more quickly when it gets busy. Any new mail requires that the mailbox and the new message be appended to the end of the data file. Each new message to the same user in a short period of time means more and more space at the end of the data file, even though there is a lot of free space inside the data file, but is not big enough to accommodate the users mailbox and the new incoming message. When a message is deleted, the user's mailbox is updated, which can use up to twice the mailbox size on disk, just like at message delivery time. NOTE: The message and any enclosures are not actually deleted until all users have deleted the message. Additional query words: 3.00 3.10 Mac Server Additional query words: ====================================================================== Keywords : Technology : kbMailSearch kbZNotKeyword3 kbMailATN300 kbMailATN310 Version : WINDOWS:3.0,3.1 ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 1999.