Why did corporate Gmail send everything to spam?

Question

gmail

Corporate mail Gmail worked perfectly, but yesterday the letters of all employees with postscripts for several years moved to spam. Why did this happen and how can the problem be solved?
For some letters, it is not possible to recover, because after recovery they again fall into spam.

Answer 1

In the mail filtering settings there is a checkbox "Never send to spam". Select letters, create and everything will be fine.

Answer 2

Issue resolved. It's all Bitrix's fault.