Email provider for home server alerts - Lemmy

Nextcloud, Qbittorrent, Truenas and loads of other svcs take optional email credentials for sending alerts and other features (eg. password recovery for nextcloud). What email providers do people usually use to make this process simple to set up? For example, Microsoft doesn’t allow basic auth anymore so it’s supposedly not possible to use via most of these setups, and some other services seem like they have a low inbox size (does this matter?)