FreeBSD, Postfix why are emails not from the domain coming with a delay?

Question

FreeBSD

The structure is as follows - an adsl modem, a cisco 5505 firewall, a cisco switch, a streaming server on fribsd, and working Windows PCs, one of which has a thunderbird sweat client installed, so the season has passed, everything worked fine, I think I'll clean the mail server. from dust, and at the same time the battery ran down, changed, and so after this procedure, for some reason letters not from the working domain, namely from simple mailers (Yandex, Google) began to arrive in the client when I wanted, sometimes after a minute, sometimes after 1 hour, 3 hours ... moreover, the departure from me goes perfectly on time, but they come with a delay, I set the correct time in the BIOS, I looked at the date in the fryah everything is correct, in Linux I’m completely newbie help, what could be the problem?

Answer 1

The gray sheet most likely works, look at the logs.
Most likely your server says to unknown recipients go to *y* come back in 15 minutes, if it comes it's normal, it doesn't come, it means spam.
And even despite the fact that everything started after cleaning - well, it coincided like that.