Sending e-mails all evening and on evenings is bad business etiquette. The person sending them seems desperate for attention but they are going overboard and it is likely to backfire. Skinmedica management puts up with it but many other companies would not.
Unless the email is an emergency and you actually have people waiting to hear back from you, then I advise you hold off on it till the next day. It's also OK to send it if your colleague lives in a different time zone where it's daytime to your night. Here are reasons against sending late-night work emails:
•They most likely won't read it until the next day. If it's related to work, many people often tune out of their work life once they are home. There are a lot of people who either resolve to not check their work emails after work, or not to respond to any work emails until they're back at the office. You're most likely not going to get a response if no one is waiting on you, so hold off on emailing
•You'll be reminding them of work during their downtime. Even if your colleague checks her email after work, you don't want to add an additional stressor and remind her of the daily grind that they're trying to escape from.
•The a.m. time stamp is a little iffy. Even if you're more of a night owl, keep those habits to yourself and try not to send off an email at 1 a.m. It might make people wonder what you're doing up in the middle of the night.
•You're more prone to making mistakes. The worst typos come out late at night when you type an email while you're feeling really sleepy. Save yourself from some sloppiness and send the email in the morning. You also don't want to make a mistake and send an email meant for your friend to your boss.
•You should be sleeping. You need to learn to let go of work and to switch out of the 9 to 5 mode when you're at home. Tackling work emails might make it harder to switch out of work mode.
•The alert might wake the reader up. The recipient of the email might leave her smartphone on at night, and if her incoming emails send sound alerts to her cell, the sounds might wake her up from her peaceful slumber.