You wanna know what irks me? People who include their educational and professional credentials in their email signatures at work - it's one thing if it's a generally accepted practice in the organization, but when it's not, then it just reeks of insecurity.
The perfect example is this manager who recently joined our organization who I had to train to do a quarterly report. The instructions and links in the binder are clearly identified and cross-indexed because it's reviewed by our auditors yet the guy had to book a meeting with me to ask me a question that could have easily been answered if he had just flipped the page. And this guy is a manager? Where's the initiative here?
He sent me an email request about something else and that's when I noticed he signed his email "D@&!% M#^?@, MBA, CMA." He makes me embarassed to be a CMA myself.