school not sharing teachers email address

[springrises]

there have been some low level bullying incidents this year and I wanted to get in touch with my daughter's form tutor (year 6) because when I call, they don't call back.
I'm also a bit unsure about sending such a personal email to a general inbox which any school secretary can read. School have just sent a response to me, saying they don't give out teachers email addresses and asked me to write out whatever it was and send it to the school general info email address.
I'm wondering what kind of communication you have at your schools? I rarely email school, but in the past have been able to email a teacher directly. You can't phone them because they're teaching and then they often phone me back when I'm at work or miss the call, so email seems like a more logical way to communicate. Is it normal for primary/middle schools to refuse to give out the teachers email address?
Communication is generally poor from this school, so this is part of a bigger picture.

DC's school staff emails are their first name dot last name so easy to work out - plus they don't mind getting emails as long as they're not expected to reply that day.

Totally normal, you send an mail to the office with FAO <teacher's name> in the subject. The only person I have a direct email for is the SENCO, and she gave it to me as was trying to co-ordinate with a lot of therapists etc.

We have an email for each teacher and the mobile number of the class mobile. One
of the class teachers communicates via email, the other by WhatsApp. Our school
office is only open two mornings a week though. Emails and the class mobile are only answered 15 minutes before the start and 15 minutes after the end of class.

Homework is set over an app and submitted in class.