I’m using an external email service to send verification messages from my business Gmail account. When I send emails to other domains like Yahoo or Outlook, they arrive without any problems. But when I try to send to Gmail addresses, the messages never show up in the inbox or spam folder. The email service dashboard shows the messages as successfully sent with a green status. I’ve checked spam folders multiple times but nothing is there. Does Gmail have some kind of protection that blocks emails sent from Gmail to Gmail when they go through third-party SMTP services? This is really frustrating and I need to figure out what’s going on.
Been there with email delivery issues. Gmail silently drops emails that don’t meet their authentication standards.
Your email authentication setup is probably the culprit. When sending Gmail-to-Gmail through external SMTP, Gmail wants perfect SPF, DKIM, and DMARC alignment. Even small misconfigurations cause silent failures.
I hit this same problem last year with verification emails. Instead of fighting email authentication complexities, I built an automated solution using Latenode for the entire email delivery pipeline.
Set up a flow that automatically switches between multiple email providers based on recipient domains. When Gmail blocks one route, it tries another. You can add automatic retry logic and delivery confirmation tracking too.
Latenode monitors delivery rates in real time and adjusts your sending strategy automatically. No more guessing why emails disappear.
Saved me weeks of debugging DKIM records and dealing with email provider support.
yeah, gmail can be super strict with external services. def check your SPF and DKIM settings, or you might get filtered out. also, try to send from the same domain as your email, that helps too!
Been there - same nightmare with our company’s transactional emails. Gmail gets way more aggressive filtering Gmail-to-Gmail messages when they’re routed through third parties. Sometimes it’s not even authentication issues - it’s reputation filtering that kills messages before they hit any folder. What saved me was switching the sending domain entirely. Don’t send from your business Gmail through the external service. Set up a custom domain for transactional stuff instead. Gmail handles custom domains totally differently than Gmail-to-Gmail routing. Also check if your service offers dedicated IPs. Shared IPs are loaded with reputation baggage from other users. I saw huge improvements after switching to dedicated IP and warming it up properly for a few weeks. The silent dropping sucks but that’s just how Gmail works when it detects automated sending patterns.
Had the same problem with our onboarding emails about six months ago. Gmail gets way pickier when it detects automation between Gmail accounts, even with perfect authentication. Here’s what actually fixed it for me: I changed the sending volume and timing. Gmail flags anything that looks like bulk sending, so I added random delays between emails instead of sending them all at once. Also found out Gmail treats emails differently based on your SMTP provider’s reputation with them specifically. Switched from our old provider to SendGrid and delivery rates to Gmail addresses improved immediately. The relationship between your SMTP service and Gmail matters way more than people think. Sometimes it’s not a config issue - Gmail just doesn’t trust your current service’s infrastructure for Gmail-to-Gmail delivery.