Jira does not send outgoing emails, notifications for the client.

[Cortel LLC]

Hello!
Jira does not send outgoing emails, notifications for the client.
At the moment, emails are definitely not sent to the domains @ inbox.ru, @ ittobiz.com
And there are many more such domains.
Due to the lack of access to SMTP logs of outgoing messages, it is impossible to understand whether the Jira SMTP server tried to send letters to these e-mail addresses and what the problem is.
Because of this, working with clients is impossible, since clients do not receive our messages and notifications.
Please solve this problem, as the product cannot be used at this stage!

[Boris Berenberg - Atlas Authority]

I think the only people who can help with this would be Atlassian Support who can unblock email addresses.

If you need an alternative email system, check out Notification Assistant for Jira