Problem:
Gmail has an almost entirely automatic spam filter. Sometimes this can create a problem with emails that are not spam but may appear to be to an automatic filter; often this can include machine-generated emails that include little text or do not appear to come from the correct domain.
Solution:
While Gmail has no explicit list of safe senders, it is possible to duplicate this functionality using filters. First, make sure that the sending email address is not blocked, then create a filter directing Gmail to “Never send to spam.”
Procedure:
Ref: https://support.google.com/mail/thread/2928386?hl=en
- Log into your Gmail account.
- Click on the gear icon in the top right of the page, then click “See all settings.”
- Click “Filters and Blocked Addresses.”
- In the section “The following email addresses are blocked. Messages from these addresses will appear in Spam,” Ensure that the address you would like to mark as safe is not listed. If it is, select it and click the button marked “Unblock selected addresses.” This may be all you need to do; if subsequent emails from this sender come to your inbox, you can stop here. Otherwise, proceed to the next step.
- In the section “The following filters are applied to all incoming mail,” click on “Create a new filter,” and add the address you’re having trouble with in the From field. Click “Create filter.”
- Check the box next to “Never send it to Spam,” and click “Create filter.” Incoming messages from the address you entered in step 5 should now go into the inbox rather than the spam folder.
Limitations:
Spam email can be sent with spoofed email addresses, i.e. the From address might match the one you filtered in the procedure above. This would allow a spammer to bypass Gmail’s spam filter and send spam directly to your inbox. In general, it is a good idea to be wary of any email you receive, even if it appears to come from a trustworthy source. Spam or phishing emails can be crafted to appear very legitimate, including a valid-looking sender email address, message content, and images. It is best to avoid clicking on links in emails if at all possible, as links are frequently used to fool users into entering their passwords into very realistic-looking login pages that ultimately steal the information for later use by an attacker.