This is a simple solution and should help with overall deliverability for your email marketing messages.
To start, log in to your Gmail account and go to your spam folder.
Scan the subject lines to see if you recognize any of the senders or topics you are actually wanting to receive. Open the email. You will see a box at the top of your message that looks like this:
When you click “Report no spam”, the message will be moved from your spam folder to your Inbox. This will help you teach Gmail that you want to receive those messages.
We recommend subscribing to your own autoresponder campaigns with your Gmail address and going through this process for any of your messages that get incorrectly delivered to spam in Gmail.
This is one quick and easy step you can take to impact your overall deliverability for your email marketing messages.
For more tips on improving your email marketing deliverability beyond unmarking spam in Gmail, check out these articles:
How To WhiteList an Email Address
Why Does Email Get Delayed?
Email Marketing: Single Optin vs Double Optin
How To Improve Your Email Marketing Open Rate
Improve Optin Rates with a Custom Confirmation Message
Managing Gmail Promotions Tab
How Content Affects Deliverability
How To Avoid Spam Filters
Why Does My Message Go To The Spam Folder?
How To Unmark Spam in Yahoo