email appears @host.domain

I have ISPConfig v2.2.32 with 32 domains. It's all ok, but I see that:

Some domains, when look at email address, show [email protected] instead of user@domain
hostname is name I put in ISP Site - Basis - Hostname

The user does not have problem, but I concerned
That can be? (sorry my english)

 

You must set the correct sender address in your mail client.

 

forgiveness, me not explain well. When I make new user in ISP Site - User&Email - New - Email Address y look after @ a hostname.domain
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PD(Thanks for reply)

 

ISPConfig automatically configures all possible email addresses. If the web site has the address www.example.com and the Co-Domain example.com, then you automatically get the email addresses
[email protected] and [email protected], although only [email protected] is displayed.