If your email recently delivered to Junk or Spam folder of Google Email, therefore you need to ask recipient to do some things. Basically if you already ask technical support for help but the issue keep arise, a workaround from recipient end is needed.
For your information, Google has developed their own filtering email system. Sometime, emails might went to Inbox or to Spam folder.
In this case, Google has advised to create own filtering system under recipient end.
1. Log in to your Gmail account.
2. Click the GEAR icon at the top right and then click SETTINGS.
3. Go to FILTERS AND BLOCKED ADDRESSES and click CREATE A NEW FILTER.
4. In the FROM section, type the email address of the sender that you want to keep out of your Spam Folder.
5. Click CREATE FILTER.
6. Tick NEVER SEND IT TO SPAM and ALSO APPLY FILTER TO MATCHING MESSAGES boxes.
7. Click CREATE FILTER again.
And you are done.
This article taken from : https://support.google.com/mail/answer/6579