There is no doubt that, as a business person, you have been using some sort of Email marketing campaign. Interestingly, there are many myths that surround Email marketing campaigns and it is a good idea to dispel them here and now.
Email marketing can be very tricky. If you inundate people with too much Email, they may get really angry with you and report you as a spammer. On the other hand, you want to send effective and valuable Emails that elicit the type of response that you are hoping for.
If you send out professional Emails through a mailing list, the chances are very good that some of the people on your Email recipient lists will unsubscribe at some point. It is absolutely inevitable.