Feature Request

Context

1. When using the example from the documentation with cron tasks inside the container, I receive information about the execution of these tasks by email.
2. In the variant with the Xapian plugin, in step 5 it is proposed to add a system cron task. I would like to add as a possible option 6 with cron inside the container as it was done here

Is your Feature Request related to a Problem?

1. To some extent. At first, I didn't quite understand why I was getting these messages, but after "google" my problem, I found out that cron can actually send messages and found ways to solve it.
2. Nope

Describe the Solution you'd like

1. I found solutions here and here + check man cron which has a mention of this behavior. I suggest adding MAILTO="" to the cron task with spamassassin configuration, as well as to my second suggestion, if it is accepted.
2. Write a process about the same as with spamassassin example in faq

Are you going to implement it?

Yes, because I know the probability of someone else doing it is low and I can learn from it.

What are you going to contribute??

PR with an edited addition to the documentation

Additional context

Alternatives you've considered

Description in 1 case below in the example that you will receive emails from cron every day with the result of this task (6 emails in the morning, xd)

Who will that Feature be useful to?

All by default. Some will not need it, for this you should leave a description of what MAILTO="" does.

What have you done already?

I tested option with MAILTO="" and the option with > /dev/null 2>&1. Both are working and I have not received any more emails in my installation.