As someone who runs a discussion e-list server for a small volunteer org, Gmail has not been an issue with a good config, generally. The other big providers are

As someone who runs a discussion e-list server for a small volunteer org, Gmail has not been an issue with a good config, generally. The other big providers are annoying, to varying degrees, often silently dropping email. ISP email tends to be a pain in the neck, putting one on a blacklist if you exchange email with two different addresses they provide service to within one hour, though at least they tend to be noisy about it.