Have you had any issues with your outgoing emails being flagged as spam by gmail?
It's been about 99% fine. I do remember last year noticing that my parent's gmail flagged (an admittedly very short) email of mine as spam, but when she went into her spam folder and told gmail it wasn't spam, all was fine from then on. I think it probably goes a long way to have SPF/DKIM/DMARC correct and doesn't hurt that it's AWS' mail servers.