Recently Apple released the final version of its new desktop operating system. Update macOS 10.14.4 had to fix a number of bugs, but instead brought problems. In particular, on the Apple forum there were complaints of wrong work Google mail.
Judging by the user feedback, the update of Apple’s desktop platform prevents the authentication process from a Gmail account using the built-in Mail app. While in the Safari browser, the service continues to work.
Also, note that even if the problem does not appear immediately, it may occur after any computer restart. The official Apple mail app may simply demand to log in to Gmail.
It is difficult to say how widespread the problem with the mail service of Google. Among the Russian-speaking Mac owners are those who have Gmail working fine, and those who are faced with problems.