Answer:
Four types of errors program should test for user input are given in explanation
Explanation:
1. Program should test that extension contains exactly three letters
2. Program should test that extension doesn't contain any number or special character
3. Program should test that extension doesn't contain any white space
4. Program should test that extension doesn't contain any punctuation mark
Answer:
Plain text, Rich Text, and HTML format
Explanation:
In Outlook 2016, three formats are allowed. You can send the plain text only or you can send using the Rich text format. However, there is another sending format as well that is allowed, and it is the HTML format. And by default, if you will let the Outlook choose the most appropriate sending format then the email message will be sent using the HTML format.
