I'll try to be a bit vague as I know this person is doing a nice thing, and I don't wish to hurt any feelings.
My sons attend a class which is run by volunteers. They do all the admin via email and there's a fair bit of it, at least once a week of things which require action from me and other parents or just general information. Every. Single. Email. is followed up by a text 30 seconds later telling me there's an email. I believe they work (assumption of course) and this is always done either early in the morning, before 7am or late ish (after 10pm) and it's annoying! I've never not responded on time to the emails.
Yes I do have more important things to worry about. yes I am thankful for their time and effort to the class. Yes it's very minor and a non issue. But my god it's annoying!