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Is it possible to add a 500 MB attachment to a message? RRS feed

  • Question

  • Hi,

    I get a client's PST file, where there is a message containing a 500 MB attachment. I just wonder how he adds the attachment to the message. Is there a size limit on the attachment size in PST file? Based on MAPI, if using IMAPIProp::OpenProperty, it seems that there are no size limit on the attachment size.

    Saturday, January 4, 2020 12:19 PM

Answers

  • Hello,

    You are right, there is no limit in Extended MAPI. But Outlook 2013 and later versions have a default attachment size limit of 20 megabytes (20480 KB) for Internet email accounts. This limit prevents your computer from continually trying to upload very large attachments that exceed the limits of most Internet service providers. This limit applies whether you are adding one large attachment that is greater than 20 megabytes (MB) or several attachments whose sum total size is greater than 20 MB.

    You may change the limit by navigating to the following windows registry hive:

    HKEY_CURRENT_USER\Software\Microsoft\Office\x.0\Outlook\Preferences
     

    Add the following registry data under this subkey:

    Value type: DWORD
    Value name: MaximumAttachmentSize
    Value data: An integer that specifies the total maximum allowable attachment size. For example, specify 30720 (Decimal) to configure a 30-MB limit.

    Note, you need to specify a value of zero (0) if you want to configure no limit for attachments.

    If you are using an Exchange Server mailbox, you receive this error message (by default) if you attach one or more items to a message, and if the sum total of the attachments is greater than 10 MB (10240 KB). This attachment limit is not related to the limit in Outlook for Internet email accounts. This limit for an Exchange mailbox stems from the Maximum send size setting that is configured in the Transport Settings Properties dialog box by the Exchange administrator.

    Read more about that in the "Attachment size exceeds the allowable limit" error when you add a large attachment to an email message in Outlook article.


    profile for Eugene Astafiev at Stack Overflow, Q&A for professional and enthusiast programmers

    • Marked as answer by tempc Tuesday, January 7, 2020 7:21 AM
    Saturday, January 4, 2020 7:14 PM

All replies

  • Usually the max email attachment size is around 20 meg
    Saturday, January 4, 2020 12:58 PM
  • Hello,

    You are right, there is no limit in Extended MAPI. But Outlook 2013 and later versions have a default attachment size limit of 20 megabytes (20480 KB) for Internet email accounts. This limit prevents your computer from continually trying to upload very large attachments that exceed the limits of most Internet service providers. This limit applies whether you are adding one large attachment that is greater than 20 megabytes (MB) or several attachments whose sum total size is greater than 20 MB.

    You may change the limit by navigating to the following windows registry hive:

    HKEY_CURRENT_USER\Software\Microsoft\Office\x.0\Outlook\Preferences
     

    Add the following registry data under this subkey:

    Value type: DWORD
    Value name: MaximumAttachmentSize
    Value data: An integer that specifies the total maximum allowable attachment size. For example, specify 30720 (Decimal) to configure a 30-MB limit.

    Note, you need to specify a value of zero (0) if you want to configure no limit for attachments.

    If you are using an Exchange Server mailbox, you receive this error message (by default) if you attach one or more items to a message, and if the sum total of the attachments is greater than 10 MB (10240 KB). This attachment limit is not related to the limit in Outlook for Internet email accounts. This limit for an Exchange mailbox stems from the Maximum send size setting that is configured in the Transport Settings Properties dialog box by the Exchange administrator.

    Read more about that in the "Attachment size exceeds the allowable limit" error when you add a large attachment to an email message in Outlook article.


    profile for Eugene Astafiev at Stack Overflow, Q&A for professional and enthusiast programmers

    • Marked as answer by tempc Tuesday, January 7, 2020 7:21 AM
    Saturday, January 4, 2020 7:14 PM
  • Hi, Eugene,

    Thank you very much for your detailed answer.


    Tuesday, January 7, 2020 7:22 AM