[Exim] Question about aliasfile explansion

We have some mailing lists in the /etc/aliases file. An example is:

list:    user1,user2,user3

The problem is that when f.x. user1 sends a mail to list@mydomain, it
recieves a copy of it's own mail.

I've looked through the docs, but can't find out how to avoid this.

Anyone who can point me in the right direction?

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