When and how should I use multiple exclamation marks?

Question

Now, I never do this, but in some few cases I have seen people use multiple exclamation (or question) marks like this: > Hey!!! Is that grammatically correct? (Or just okay). In case it is, *how many* marks are grammatically allowed/accepted?

Answer 1

From the Internet:

Here are sensible guidelines for the use of exclamation points in business:

1. Use sparingly. ...
2. One is enough.Multiple exclamation points suggest that you are really worked up—they're the verbal equivalent of hitting someone over the head. ...
3. Don't combine with other punctuation marks. ...
4. Consider the context.

Answer 2

Multiples are for emphasis in casual communication. One mark should be used in formal writing. So, it's ok in a text, but not in a business letter.