Identifying those on vacation for messages in notifications

When someone is on vacation, it is not possible for others to know about it when they tag someone in notifications. That would be useful to inform colleagues that a person is on vacation and tagged as such when writing to them in the notifications. Lately, a colleague wrote to me and there was no way she can see that I was on vacation. It is someone else that had to inform this colleague that I was out of the office. It can be editable so the person can write personal information: out of office - on vacation - back on XXX, or else. Emails have that, and other apps do have that feature too. For example, Slack is one of them. 

Thanks for considering.