It takes a long time to send postfix mail, what should I do?

Question

postfix

Friends, I am a teapot in all these matters.
Received the server from the system manager. Now people are complaining that mail is not working well.
We have postfix admin 2.91 on CentOS.
I logged into the admin panel and sent myself an email from there. the page loaded for about 2 minutes. Then I found commands on the Internet to check the mail and
it’s not clear, but I see that it says lost connection with 127.0.0.1 :( I understand that the connection is lost, but it works further. And yes, the letter constantly adds "mailq" command.
Before that, I stuck in the queue, there were letters, for a week, 197 pieces.
I don't know if it should be so or not.
I cleared the queue.

I'm sure the problem is simple, but I don't know the solution .