Yes — you're definitely not alone. Many users of QuickBooks Online (QBO) have reported intermittent issues with invoice emails being marked as undeliverable or not reaching clients, and this seems to be a recurring issue, especially around:

• Changes in QuickBooks' email server IPs

• Tightened spam filter rules by recipient mail servers (like Gmail, Outlook)

• Missing or misconfigured sender domain settings (SPF, DKIM, DMARC)

• Clients accidentally marking previous emails as spam

I understand your sentiment about the recurring email delivery issues, Ssullc.

I recommend contacting the QuickBooks Online live support team. Email delivery issues can arise from various factors, and our phone support may offer specific guidance tailored to your situation.

Here’s how you can reach them:

1. Go to the (?) Help icon in the upper right corner.
2. Select the Search tab and hit Contact Us.
3. Click the Ask about something else tab.
4. Type in your concern and hit Continue.
5. Choose a way to connect with us:
   • Have us call you - Get a call from a support expert.
   • Chat with us - Start a conversation with a support expert.

Check out their support hours to determine their availability.

If you have any follow-up questions, please feel free to leave a comment below.