If you are new to online dating and a man then you should be warned. Most women get hit with a lot of lewd, pointless come-ons every day. So if your message to them is weak or even has the slightest hint of being cheesy, they don’t have time, they already have enough of that kind of email to delete.
The only way for a man to be successful is to read the woman’s profile in detail. Don’t just stop at their profile picture, it’s natural, but you want to let them know you got past their looks to find out more about them. Try to find something that you have in common and make the message about that.
If you don’t put any thought into your message to her then she isn’t going to put any thought into hitting the delete key automatically. You have to make your message stand out. You can also try your hand at complimenting her, but don’t, whatever you do, make it a ham handed compliment. Don’t make the compliment about her appearance; make it about one of her interests. You could even try some humor to break the ice as long as it is appropriate.