While the first secret of any covering letter, or in today’s market email, is that most of them don’t get read.
However, there are one or two real essentials. Few of us are as good at writing as Leo Tolstoy. So writing War and Peace is never a great strategy. If people don’t read short cover letters, then they most assuredly don’t read mammoth ones.
The second secret, certainly as far as emails go, is that the subject line must be clearly labelled so your recipient understands that this is an application for whatever job, department or division you are applying for.
The third secret is that people get really upset if you spell their name wrong. So take the time to get this piece of information exactly right, as well as the name of the company.
The fourth secret is to read the job advertisement or specification. The company might be using artificial intelligence, or perhaps resorting to a human in HR, to sift the replies. Make sure the reasons that you are applying for the job, and indeed your commentary about yourself, reflects the job description. Make sure it explains, if you don’t have quite the qualifications or experience they are looking for, why you have more than enough experience to make up for that.
The fifth secret is simply to get yourself a professional email address. email@example.com or firstname.lastname@example.org is hardly professional. And we have seen much worse.
But Gmail, like many others, will give you a free email address at any time to manage your job applications. Make sure you do so if your current email address is one that is very definitely not quite right for your professional life.
Cover letters are not nearly as important as they used to be. But avoid a couple of mistakes, make sure they are not too long and make yourself look and sound professional will be just fine. The CV is the important thing, make sure that is right to begin with.