Effective maximum mailto: body lengths

The standard doesn’t define a maximum length, leaving implementation up to browsers and mail clients (See IETF RFC 2368).

Microsoft products do have set limits:

  • IE GET limit is 2,083 http://support.microsoft.com/kb/208427
  • Outlook express: 456 characters http://support.microsoft.com/kb/q182985/

Other browsers are likely to work up to lengths beyond that of a reasonable email body. The iPhone doesn’t have a documented limit, but works with up to 1MB of text.

Modern browsers that support data urls (everything except IE<9) should be fine.

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