Using a computer (not a mobile device) log into your Gmail account and look in your spam and junk mail - mark emails found in here, that should not be here, as NOT SPAM. Open the email or select the email which has been incorrectly marked as spam by Gmail and click on the "Not spam" button.
The email will be moved to your Inbox and Gmail will remember your decision. If Gmail again marks future emails from the same email ID or domain as spam, repeat the steps again. Repeating it a few times will teach Gmail that the emails are important and should not be marked as spam.
1. Click on Gmail logo and select "Contacts" option.
2. Now click on Add contact button and enter the desired email address. Next, click the "Add" button. This should prevent Gmail from marking future emails from that email address as spam.
If Gmail consistently marks legitimate emails as spam, you'll need to create a filter so that Gmail never sends those emails to the spam folder. This can be accomplished in several ways, one way is outlined below.
1. Select an email and click on "More -> Filter messages like these" option.
2. This will open a drop-down box in search box containing the email ID in "From" field. Click on "Create filter with this search" link given at the bottom-right corner of the drop-down box.
3. Now enable "Never send it to Spam" checkbox and click on "Create filter" button. Now Gmail will never mark any email from that particular email ID as spam.
For more options please see full article at http://www.askvg.com/fix-gmail-marks-your-important- emails-as-spam/.
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