Yes, but it can be involved and one mistake means your email could potentially never make it to peoples inbox as it will be seen as spam, etc. Not even mentioning that if your server was offline for an extended period of time (e.g. 2-5 day vacation), you could lose incoming messages.
They can also read your more personal emails if the other party uses gmail regardless of what you use. The best you can do is try to distance your different “online personas” by separating personal emails, purchases and other use cases keeping Google out of as many as you can without needing other people to also jump ship.
Kind of matters to some of us whose parents can’t go to the grocery store without being profiled despite all things being in order because of how they look to other people.
“Whoops we meant dissatisfaction, small typo…” - HP (Horrible Printers)