I think it’s more likely that this is just a case of people using something as evidence for whatever they already believe. If an important person sends an email with spelling or grammar mistakes, you attribute it to them being busy and not thinking you’re important enough. If an unimportant person sends an email with spelling or grammar mistakes, you think it’s because they’re stupid or lazy.
However, personally, I think spelling and grammar mistakes in emails always signals something “bad,” whether it’s that they don’t pay attention to detail, don’t have respect for who they’re talking to, are not intelligent, etc.
I think it’s more likely that this is just a case of people using something as evidence for whatever they already believe. If an important person sends an email with spelling or grammar mistakes, you attribute it to them being busy and not thinking you’re important enough. If an unimportant person sends an email with spelling or grammar mistakes, you think it’s because they’re stupid or lazy.
However, personally, I think spelling and grammar mistakes in emails always signals something “bad,” whether it’s that they don’t pay attention to detail, don’t have respect for who they’re talking to, are not intelligent, etc.