Hi @Strawberry.
Thanks again. Can't think I've done anything 'verboten' like that. They've been the same general enquiries I've always sent – possible dates, times, a bit about me and what I'm looking for – which has met with okay response.
Could be inactivity. Like the OP, I stayed pretty quiet during the 15 months of lockdown (no emails since Dec 2019). So, maybe they think my account is spamming after a period of inactivity. (Although 5x emails is hardly spamming!).
Hey-ho. It's either take to the phone (#nervous, feel like I come across better in email!), or wait a few days before getting back in the game.