Debian – Postfix – disabling local delivery correctly

I have a postfix server with a config for no local delivery. Every email sent through from websites on this server are beeing sent out, no domain on this server accepts emails localy (every domain has external mailboxes – Google, Outlook, etc.). It works fine for every domain (does not matter if the domain is hosted on this server or not), emails are sent on mailserver based on domain DNS entries. Every domain but the one set up as server domain in hosts.

So I have the server domain xxxx.tld and other domains 111.tld, 222.tld… When there is an email for …@111.tld, …@222.tld, etc. it is going out correctly and it is delivered to external mailbox with no trouble at all. When I send an email to anything@xxxx.tld, this email stays on the server with a messages deferred – mail transfer unavailable. I have followed many instructions and tried many configs, but I am not able to get the emails for xxxx.tld in external mailbox (as in domain DNS entry), in this situation it is Google.

I am sure it is just a simple thing, but I am blocked, I cannot find it. Can you help me?

Thank you very much.

This is my main.cf

myhostname = web.xxxx.tld

mydomain = xxxx.tld 

alias_maps = hash:/etc/aliases, hash:/var/lib/mailman/data/aliases

alias_database = hash:/etc/aliases, hash:/var/lib/mailman/data/aliases

myorigin = /etc/mailname

mydestination = $mydomain, mail.$mydomain, localhost.$mydomain, localhost, localhost.localdomain

mynetworks = 127.0.0.0/8 [::1]/128

This is my master.cf – everything standard but local disabled

#local     unix  -       n       n       -       -       local