To Whitelist an Expected Mail in Advance:
If you are expecting an important mail from a person whose email address you already know then you can white list that ID so you can be sure that the mail would not escape to spam folder and will definitely land into your inbox. For this, click on “Contacts” from your Gmail window. Then select “Add contact” and “Save” it after filling out necessary details. Now, that contact becomes safe address and email from it will always come directly into your inbox.
To Quickly While list a Particular Sender:
If you find an important mail in spam folder then you can quickly instruct Gmail not to move such mails from inbox by just clicking onto “Not Spam” button at the top of the mail. The selected mail would be moved to inbox immediately and it would be added to white list forever.
If you suspect that your mail in inbox would be marked spam by Gmail team, then you can make sure that this doesn’t happen clicking on “Reply button” drop-down and adding it to contact list.
To Whitelist Multiple Addresses in Gmail:
You can make use of filtering feature of Gmail to whitelist multiple email addresses. Suppose that you want to add your company domain address in whitelist so that you never miss any important mail from your company then all you need to do is to apply an appropriate filter.
Go to “Settings” in Gmail, and then click “Filters“. Create a new filter and type the domain you want to whitelist in “From” field. For example “@mycomany.com”. Click on “Next Step” and then check “Never send to spam”. Finally, click on “Create filter” and you are done. If you want to add certain group of email addresses as trusted source, then use above filtering technique with “email1@example.com OR email2@example.com” and so on in “From” field. Note: The amount of spam mails you receive depends on where you have distributed your email address. As a word of caution, never submit your mail to unreliable websites or write it publicly on internet. A workaround for situations when you need to give your Gmail ID is either writing it in only-human-readable form that is, myemailid [at] gmail [dot] com or using Gmail plus feature that is, myemailid+blog@gmail.com. This mail address will also redirect to your original address however, you can set filters to control it.