Gmail allows you to create a list of contacts, to which you can send the same email at once. However, the Gmail mobile app does not allow you to create mailing lists, or even select a pre-existing one.
Steps

Step 1. Open the contacts page
Using a browser on a computer, go to your contacts page. If you are signed in to Google, this will open your Google contacts page.
- If you are not already signed in to your Google account, enter your email address, when prompted, and click Following, then type your password and click again Following to connect you.
- If you are logged in to another account, click on your profile icon at the top right of the window, then select your account or click on Add an account and type in your email address and password.

Step 2. Select the contacts
Hover your mouse cursor over the profile picture (or initials if there is no picture) of one of your contacts. Check the box that then appears instead and repeat the operation for each contact you want to add.

Step 3. Open the Labels menu
Click on the icon Labels

which is at the top left of the page. A drop-down menu will then appear.

Step 4. Click Create Label
You'll find this option at the bottom of the drop-down menu. After clicking on it a popup window will open.

Step 5. Enter a name
Type in whatever name you want to name your mailing list. This is the name you will enter in the field TO when you write an email to send to this list.

Step 6. Click Save
The button is located in the lower right corner of the window. By doing this, you will save your mailing list under the label you assigned to it.

Step 7. Open your inbox
Go to Gmail and re-enter your email address and password, if prompted.
You must sign in to the same account that you created your mailing list for

Step 8. Click New Message
This is the button at the top left of your Gmail inbox. This will open the window New message.

Step 9. Type the label
Enter the group name in the field TO from the window New message. You should see the name of the group and a preview of the contacts it contains below the field TO.

Step 10. Select the group
Click on the name of the group that appears below the field TO to select it as the recipient of your message.

Step 11. Write a message
Enter a subject in the field Object, then write a message in the text field below.

Step 12. Click Submit
This is the blue button in the lower left corner of the window New message. This will send an email to every contact on your mailing list.
Advice
- Using the field CCI instead of the field TO, contacts won't be able to see other recipients in your mailing list.
- You can also access your contact list by clicking on ⋮⋮⋮ in the top must corner of the Gmail page, then clicking More at the bottom of the window that will appear and finally by clicking on the icon Contacts.