Not even presidents are expected to refer to themselves with their titles.
A White House reporter called out Manigault for referring to herself as the "Honorable Omarosa Manigualt" in her invitation to the Congressional Black Caucus, in which she requested them to meet with her and Trump. The CBC declined the invitation, stating the meeting would not be productive.
Manigault replied with a chart of salutations, which indicates that people corresponding with certain public officials are expected to use "Honorable" in the official's physical address.
Not even presidents are expected to refer to themselves with their titles. For instance, Barack Obama closed out letters with just a signature and no title or formal closing whatsoever.
Despite a role in Trump's White House as communications director, Manigault seems to be having a bit of trouble with those duties.
She engaged in a back and forth with Twitter users over the gaffe, but has yet to respond to her misinterpretation of the title rules. While she claimed she "will always take time to educate" people, it doesn't seem like she has much time to be educated herself on her new role.
Taking after her boss, indeed.