The author's personal mail server has been having issues with emails being marked as spam by Gmail, despite having no history of sending spam and following best practices such as configuring SPF and DKIM. The author has tried various methods to resolve the issue, including registering for Google Postmaster Tools, but to no avail. The problem seems to be affecting not only the author but also other users who have reported similar issues. The author is seeking advice on how to resolve the issue and get their emails delivered to Gmail users' inboxes.