The problem is you are switching between research and writing for every single lead. That is what makes it take 4 hours. Try batching it. Do all your research first, just pull one specific thing per lead and write it down. Then close all the tabs and write all the emails in one sitting. Way faster because your brain stays in one mode instead of jumping back and forth every 5 minutes. Once your process is clean, the writing part gets quicker on its own.

Honestly the spam reports are less of a problem than people think. One or two reports won't kill your domain. What actually gets you flagged is sending the same generic message to thousands of people who have no idea who you are. Gmail watches engagement. If people are not opening, not replying, and some are reporting, it starts treating everything from your domain as noise. The real fix is simpler than most people make it. Send to fewer people, but make sure the message actually makes sense for them. A relevant email to the right person almost never gets reported because it does not feel like spam. It feels like someone actually looked at their business. Tight list, better copy, lower volume to start. Your reply rate will tell you everything you need to know.

If your infra checks out and placement looks good, the problem is almost always the copy. Reply rate dropping from 1.5% to 0.5% with the same setup usually means the message stopped resonating, not that the emails stopped landing. A few things worth checking: Is your first line about you or about them? Is your offer the same one you were sending last year? Markets get saturated fast. What worked 12 months ago in India reads as a template today because everyone copied it. Two week warmup is also on the shorter side for Google Workspace inboxes sending to Outlook and Hotmail. Push to 4 weeks minimum before judging copy performance.