Hi, good day, hello…
These are usually the most common subject lines I get in my email account. I just can’t stand them. Ever wanted to quickly glance through your mail and get to the message you wanted just by looking at the subject field? No can’t do.
Subject lines were invented for a sender to put a subject in the line, not a bloody greeting! So if your are writing a mail about a meeting tomorrow, don’t put “hello” in the subject line. The subject is “meeting tomorrow” for christ’s sake. If you can’t think of a passable subject line, then your message doesn’t have a subject at all so don’t bother sending it.
That is all.