define external switch function MailBoxIsInError
                  value MailInBox this-MailInBox

This function returns true if the last operation on the MailInBox resulted in an error, and false otherwise.

Note that any function in the Mail library can result in an error, except the following:

• MailInBoxGetStatusReport
• MailInBoxIsInError
• MailOutBoxGetStatusReport
• MailOutBoxIsInError
• MailLibraryVersion
• MailIsVersionCompatible

Argument:

• "this-MailInBox" is an opaque object of type MailInBox.

Example:

  halt when MailInBoxIsInError MyBox