Issue Cannot send emails after updating to Plesk Obsidian Version 18.0.40 Update #1

[kaxrist]

Hello,
i can't send emails from roundcube to hotmail after updating to Plesk Obsidian v. 18.0.40 Update #1. I'm getting a "Undelivered Mail Returned to Sender". There is no messages in "Mail Queue" or any other spam notifications. Also i can't receive mails from server:

Backup task finished on host ********.plesk.page.

Creation date is: 2022-Jan-11 00:01:09
Created by: Plesk administrator (type=server, guid=49ceb943-ea13-11eb-8d7c-00163c13d11c)
Created for: Server (type=server, id=1)
Task status is: error

 

[PeopleInside]

Undelivered Mail Returned to Sender is only the type of email you get. You should have more detailed error in that email with the reason why the email has not been delivered.

Are you sure the email problem is related to the Plesk update?
Are you sure you get only issues if you send email by using RoundCube?
Do you get Undelivered Mail Returned to Sender also if you send an email to a different domain and email address?