There is no doubt about it, the fear of rejection is a silent killer when it comes to sales and the key to handling rejection in sales is to understand the principal of cause and effect. Simply put, when you feel rejected [effect] there will always be something that caused you to feel that way.
Getting emotional

At the moment you probably notice that at certain times during your sales activity you feel an emotion you are calling ‘rejection’. In order to handle rejection we need to know what specific emotions you are feeling and what, specifically, is causing you to have those feelings.
Find the cause and effect

The best way to identify the emotions and triggers is to keep a diary for a week or two. Every time you feel a strong emotion, write in your diary stating what emotion you felt and what you were doing immediately prior to getting the emotion. Make sure you note down the positive emotions as well as the negative ones.
Manage the cause

If you know that certain things trigger an emotion then you can choose not to do those things anymore. However, for most this is not a practical option if paying the mortgage depends on your ability to find clients. You can try changing slightly the things that are triggering the emotions. For example:

Some people find that their emotion is triggered by negative self-talk and they can overcome the trigger by simply changing their self-talk or drowning it out with music.
Many people report that when making cold calls they get less fear when they stand and put on a smile.

Manage the effect

When you trigger an emotion, the body is pumped full of chemicals. If these chemicals are making you feel bad then you can do something about it to get rid of them. For example, burning them off through activity, or replacing them with more positive chemicals. Rather than grabbing a jam donut or smoking a cigarette you could look in your diary and do something that triggers positive emotions like thinking about your holiday or happy clients.
Break the cause and effect

The thing about cause and effect is that it is possible to change the effect or event eliminate it. To do that we need to be able to catch ourselves at the moment we are doing the thing that triggers the effect. When we do this, we are more able to control what happens. Some people advocate wearing an elastic band around their wrist which is then ‘pinged’ whenever the activity is done.
Get professional help

However, if you find that you are constantly pinging and your wrists are red raw and painful then you may want to seek out some professional help! I personally found Neuro Linguistic Programming (NLP) to be effective and the great thing about NLP is that you can change the emotion to a positive one or remove the emotion all together.