XCLN: Microsoft Exchange Message Size Limitations

Last reviewed: January 6, 1998
Article ID: Q149217
The Information in this article applies to:
  • Microsoft Exchange Server, version 4.0
  • Microsoft Exchange MS-DOS client, versions 4.0 and 5.0
  • Microsoft Exchange Windows 3.x client, versions 4.0 and 5.0
  • Microsoft Exchange Windows 95 client, versions 4.0 and 5.0
  • Microsoft Exchange Windows NT client, versions 4.0 and 5.0

SUMMARY

The following is a list of 14 questions and answers dealing with Microsoft Exchange message and attachment size limitations and the number of messages and attachments that can be stored.

MORE INFORMATION

  1. Q. What is the limit to the number of addresses in the header fields?

        A. That depends on the client platform. The Win16 limit is smaller than
           the Win32 limit, but we have tested with 1500+ on Win16 and 2000+ on
           Win32. These are total recipients because we count To:, Cc:, and
           Bcc: objects, although Distribution Lists count as 1. There is no
           hard limit, it is based on the amount of memory available on the
           client computer.
    

  2. Q. What is the limit to the number of distribution lists that can be

           included in the To:, Cc:, and Bcc: fields?
    

        A. It's the same as the limit on the number of addresses.
    

  3. Q. What is the limit to the number of attachments that can be sent with

           a single message?
    

        A. None, it's based on available disk space. There is a 16GB limit on
           the Microsoft Exchange Server store.
    

  4. Q. What is the limit to the total size of a message?

        A. The total size of the message, including attachments, is only
           limited by the 16GB Microsoft Exchange Server store limit. However,
           the text of the message is limited to 1MEG.
    

  5. Q. What is the limit to the number of Distribution List nesting levels

           for hierarchical Distribution Lists?
    

        A. None.
    

  6. Q. What is the limit to the number of folder nesting levels?

        A. None.
    

  7. Q. What is the limit to the number of names that can be contained in a

           Distribution List?
    

        A. 5,000
    

  8. Q. What is the limit to the number of items that can be contained in a

           single folder?
    

        A. In the personal folders store (PST), it's 16,000. In the Microsoft
           Exchange Server store, there is no limit. Again, it's based on the
           16GB storage limit.
    

  9. Q. What is the limit to the number of messages that can held in the

           Inbox?
    

        A. In the PST, the basic limitation is that 16,000 messages can be
           stored in a single folder. In the Microsoft Exchange Server, there
           is no limit. The administrator may set a user quota. If the quota is
           exceeded, the user will not be allowed to create or send new
           messages but they will still receive messages. The quota is based on
           size, not number of messages. In all of this, the only real limit is
           that the Microsoft Exchange Server store cannot be larger than 16GB.
           The number of messages that will fit into the 16GB is the real limit
           and with single instance storage the actual limit is much higher.
    
    10. Q. What is the limit to the number of messages that can be held in the
           Outbox?
    
        A. All folders are the same, so it's 16,000 for a PST and no limit for
           the Microsoft Exchange Server store.
    
    11. Q. Is there a limit to the number of times a message can be forwarded?
    
        A. No, however, Microsoft Exchange does perform loop detection for
           forward rules and that limit is 240.
    
    12. Q. What is the limit to the size of messages that can be sent via
           gateways or the MTA?
    
        A. None, however the Administrator can set limits at each link point
           (MTA to MTA or out gateways). If a message exceeds that limit, the
           user will receive an Non-Delivery Report stating that they have
           exceeded the size limit.
    
    13. Q. What is the limit to the number of attachments that can be sent via
           gateways or the MTA?
    
        A. None. The administrative limits can be applied here also, so limits
           can be set for controlling the throughput of a link.
    
    14. Q. What is size limit for an individual's message store?
    
        A. None. The administrator can set quotas on the Microsoft Exchange
           Server store, but that is an administrative control issue.
    


Additional query words: faq
Keywords : XCLN kbusage
Version : 4.0 5.0
Platform : WINDOWS


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Last reviewed: January 6, 1998
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