Will these unread mails never be read forever?

Whenever I look at  my mail box, I see many unread mails in there! It worries me. They wait in there for days, sometimes, for months. As if I will read, I put these at the first order to notice these after.

How many mail addresses do you have actually?

Even you don't know, you have many mail addresses.

I see some doubtful messages that are  tended to mail services' admin..
"I received some mails that belong to another person!"

Do not worry! It is a useful functionality for you!

I am going to tell it as I can!

Gmail system ignores the points within the mail username.  For example, my mail` user name is ziyahanalbeniz. Wherever you put the points on username is not important because of  Gmail system will ignore it.
If you have a Gmail account, you can try it yourself. You send an email to yourself writing your address as
"u.s.e.r.n.a.m.e@gmail.com"
"user.name@gmail.com"
"userna.me@gmail.com"

You will see, the message will be arrive your mailbox!

The Second Hint: Putting "+" sign at end of the your username, you can create many variations of your mail.

Also you can put "+" plus sign at end of  your username, so that, you have many mail addresses. You can use this functionality to manage your mail account more efficient.
For example, you think that you give your mail address to all social site as username+social@gmail.com, Then again, Gmail system also ignores plus and right of it. The mails  also will be arrived your mailbox.

Where can you use this? 

You are able to create many efficient filter to regularize your mailbox.

For example, you can say to filter,
"if the sender contains 'social',  move it in Social directory and put a 'Social' label on it."

The examples will be able to be duplicated.. But I think above is enough to understand the useful functionalites that are provided  by Gmail.