I'm surprised to read this. We just email support@[the expected domain name]. Perhaps our queries are simple enough they can be handled easily.

Probably so. My volume is around 750k email per day roughly.

Recently they started tinkering with spam filter, which worked fairly well before. Now it doesnt work - good mails go to spam, spam garbage goes inbox. Support tried - I'll give them that - but almost all their advises were either not working or working just partially.

My guess is they integrating "AI" with spam filter, hence the quality decline.

I use just use help-> Open ticket and getting one response per day (this is to address timely responses). Granted I am in UTC+7, but from company as big as FastMail you would expect support around the clock.