If you use Gmail as your email client, here are many tips to help you get the most from this program. Often you may get a notice from a friend that they are going out of town for a few days and to please hold emails. What a pain to remember (for me, anyway). If they used Gmail they would never have to send out that notice again. Gmail can hold all your emails, and keeps them for a long time. Among other advantages, Gmail isn't tied to one OS or to one device or to one mail program. It can run on any browser, in any OS, and on practically any device. You don't even need to be connected to the internet to read your emails (see tip #65).
These tips are a little over a year old, so there may have been some changes in the interim. Anyway, you might read them just to see what's available in Gmail. A bit overwhelming, eh?.