I have been using Fastmail for close to 20 years and this is the first time I’ve noticed any downtime. It’s one of the few services I’m happy to pay for year after year.
I must admit, I was unaware they've been operational for such an extensive period! Given their valuable service, I'm confident they will persist for another two decades. There's an undeniable need for email services that are independent and not subject to the whims of major corporations like Microsoft or Google.
Likewise, 20 years here. I vaguely recall some downtime in the past, so for me this might be the second time I've noticed it.
Likewise, at least 20 years and I didn't even notice this one.