Problem with Jira SD. Notifications were no longer sent to users, notification schemes and the mail server did not change. What could be the problem?

Question

JIRA

Good afternoon!
The problem is this: Jira in the company performs the function of electronic document management, with the approval of higher authorities and the issue getting to the executor of a particular issue. When creating an issue, the notification scheme contains the author and the current performer. The scheme has not changed. The mail server has not changed. About a week ago, emails to authors and performers stopped coming (although before that they had been coming regularly), but they are used to receiving them, they don’t look in the queue, applications hang on approvals. What could be the problem?

Answer 1

what's in the logs?
1. logs of the jira itself
2. separate logs on outgoing-mail, the jira has them, if not included, turn them on.
3. if your mail server - what's in its logs.