People have in their Gmail Contact List more people than they remember. You can use it to remember who you know, and to help you send the emails. Here is what you have to do:
- Open Gmail in your computer.
- Click this button
which appears in the top right corner. - In the menu which appears, scroll down, and click
- In the left side of the screen, click
A list of contacts will appear of anyone who has contacted you before on Gmail or whom you have contacted. So, what you can do is, go over them one by one, and whenever you find someone you recognize to whom it makes sense to send the email, click on their email address, and a window will pop up for you to write the email. Then, just “Copy” and “Paste” the text from this website to the email, edit it by adding the contact’s name at the beginning, and your name at the end, and that’s it. You can send it. Off to the next person.
To avoid your emails being marked as spam, please do this:
So, you when you have your email all ready, instead of clicking “Send”, click the triangle which is attached to the right of the button: 
.
Then you click: “Schedule send”, and choose different dates for each five emails.
In this way, you can send all your intended emails in one day, while they will receive them at different dates. Try to schedule about 5 emails for each date to avoid the spam filter.