Fix guides

Find your error, follow the steps, then recheck your domain free.

• Gmail 550 5.7.26 "sender is unauthenticated"
• Outlook 550 5.7.515 "required authentication level"
• SPF permerror: too many DNS lookups
• Multiple SPF records found
• "dmarc=fail" in headers
• "dkim=none" / DKIM not set up
• Gmail "via" another domain next to your name
• "blocked using Spamhaus" bounce
• Emails going to spam or junk (general)