What port need to be opened for yunohost to work

Hi
i just moved my yunohost to a new isp
on the modem box provided by “free” i did open all the yunohost listed port except those 2 :
53 and 80
as bind is not running i did suppose i could leave port 53 closed and as i will always use https i also supposed it would not harm leaving port 80 closed
however now my mail server stopped working. i also just tried to use xmpp and found it not working should i reopened port 53 and 80?
and for what reason ?
thanks
note : free blocks port 25. i unblocked it before any action

i tried to mail myself from gmail and i received the following error:

Message will be retried for 2 more day(s)

Technical details of temporary failure:
Google tried to deliver your message, but it was rejected by the server for the recipient domain domain.tld by domain.tld. [xxx.xxx.xxx.xxx].

The error that the other server returned was:
450 4.1.8 blblbl@gmail.com: Sender address rejected: Domain not found

any idea ???

I suggest to read and apply https://yunohost.org/#/blacklist_forms_fr

If it not works, could you log on ssh and try to send a mail with something like that:

mail -s test_from_command_line  user@MyDynDomain.nohost.me < /etc/fstab

User should be a Yunohost user.